How to use a string from another class in c# winform application?

So I am coding a winform app in Visual Studio C# which locks a users type message using a generated key. The user needs to know the date the key was created, which is collected from a file the program generates when the user types into "textBox1". What I am doing is using strings to verify the date the "password.txt" file is created, is the date the user puts in if not the message will not open. The problem though I am having trouble with static properties, this error:

Error CS0120 An object reference is required for the non-static field, method, or property 'Encryptor1.Encrypt(string)' UniveralWindowsTextPGP C:\Users\keife\source\repos\UniveralWindowsTextPGP\UniveralWindowsTextPGP\Form2.cs 85 N/A

Here is where I implement the encryption and decryption method:

namespace UniveralWindowsTextPGP
{
    class Encryptor1

    {
        public static string IV = "1a1a1a1a1a1a1a1a";
        public static string Key = "1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a13";

        public static string Encrypt(string decrypted)
        {
            byte[] textbytes = ASCIIEncoding.ASCII.GetBytes(decrypted);
            AesCryptoServiceProvider endec = new AesCryptoServiceProvider();
            endec.BlockSize = 128;
            endec.KeySize = 256;
            endec.IV = ASCIIEncoding.ASCII.GetBytes(IV);
            endec.Key = ASCIIEncoding.ASCII.GetBytes(Key);
            endec.Padding = PaddingMode.PKCS7;
            endec.Mode = CipherMode.CBC;
            ICryptoTransform icrypt = endec.CreateEncryptor(endec.Key, endec.IV);
            byte[] enc = icrypt.TransformFinalBlock(textbytes, 0, textbytes.Length);
            icrypt.Dispose();
            return Convert.ToBase64String(enc);
        }

        public static string Decrypted(string encrypted)
        {
            DateTime creation = File.GetCreationTime(@"C:\password.txt");

            FileInfo fi = new FileInfo(@"C:\password.txt");
             var created = fi.CreationTime;
            if (fi.CreationTime != Form2.keyhere)

// The line above is where the error is occurring in this part.

{
                string message = "That is incorrect, access is denied.";
                MessageBox.Show(message);
            }
            else

            { 
                    byte[] textbytes = Convert.FromBase64String(encrypted);
                    AesCryptoServiceProvider endec = new AesCryptoServiceProvider();
                    endec.BlockSize = 128;
                    endec.KeySize = 256;
                    endec.IV = ASCIIEncoding.ASCII.GetBytes(IV);
                    endec.Key = ASCIIEncoding.ASCII.GetBytes(Key);
                    endec.Padding = PaddingMode.PKCS7;
                    endec.Mode = CipherMode.CBC;
                    ICryptoTransform icrypt = endec.CreateDecryptor(endec.Key, endec.IV);
                    byte[] enc = icrypt.TransformFinalBlock(textbytes, 0, textbytes.Length);
                    icrypt.Dispose();
                    return System.Text.ASCIIEncoding.ASCII.GetString(enc);
                }
            
        }
    } }

// And here is the form:

  namespace UniveralWindowsTextPGP

{
public partial class Form2 : Form
{
    public Form2()
    {
        InitializeComponent();
    }

    private void label1_Click(object sender, EventArgs e)
    {

    }

    private void Form2_Load(object sender, EventArgs e)
    {

    }

    private void richTextBox1_TextChanged(object sender, EventArgs e)
    {

    }

    private void label2_Click(object sender, EventArgs e)
    {

    }

    private void button1_Click(object sender, EventArgs e)
    {

    }

    private void passwordbox_TextChanged(object sender, EventArgs e)
    {

    }

    private void richTextBox1_TextChanged_1(object sender, EventArgs e)
    {

    }

    private void Decrypt_Click(object sender, EventArgs e)
    {
        string dir = richTextBox1.Text;

        StreamReader sr = new StreamReader("encryptedmessagehere.txt");
        string line = sr.ReadLine();

        richTextBox1.Text = Encryptor1.Decrypted(Convert.ToString(line));
    }

    private void Form2_Load_1(object sender, EventArgs e)
    {

    }

    private void label3_Click(object sender, EventArgs e)
    {

    }

    private void button1_Click_1(object sender, EventArgs e)
    {
        string dir = richTextBox2.Text;




        string enctxt = Encryptor1.Encrypt(richTextBox2.Text);
        System.IO.File.WriteAllText(@"C:\encryptedmessagehere.txt", enctxt);

    }

    private void label4_Click(object sender, EventArgs e)
    {

    }

    private void richTextBox2_TextChanged(object sender, EventArgs e)
    {
        richTextBox2.EnableContextMenu();
    }

    private void button2_Click(object sender, EventArgs e)
    {
        string dir = richTextBox2.Text;

        StreamReader sr = new StreamReader(@"C:\encryptedmessagehere.txt");
        string line = sr.ReadLine();

        richTextBox2.Text = Encryptor1.Decrypted(Convert.ToString(line));
        System.IO.File.WriteAllText(@"C:\decryptedmessagehere.txt", line);
       
    }

    private void button3_Click(object sender, EventArgs e)
    {
        Form3 f3 = new Form3();
        f3.Show();

    }

    private void button4_Click(object sender, EventArgs e)
    {
        Form f4 = new Form4();
        f4.Show();

    }

    public void passwordbox1_TextChanged(object sender, EventArgs e)
    {
       

    }

    private void richTextBox3_TextChanged(object sender, EventArgs e)
    {
        string richTextBox3 = "";
    }

    public void textBox1_TextChanged(object sender, EventArgs e)
    {
        
        TextWriter txt = new StreamWriter("C:/password.txt");
        txt.Write(textBox1.Text);
        txt.Close();
        public string keyhere = textBox1.Text;

// This is where the error is occurring here.

Thank you very much, your thoughts are appreciated.