I have an authentication function which i want to detect wrong username and password condition to make a notification popUp massage

I have an authentication function which I want to detect wrong username and password condition to make a notification popup massage. I tried many codes and I find the solution but I made a new problem that won't let user log in even with correct username and password and shows the wrong identification situation, what should I do?

this is the code I wrote:

import { toast } from 'your-toast-library';

export function verifyUser(data) {
    const info = new URLSearchParams();
    const username = [data.username, data.captcha, data.captchaKey].join("|");
    info.append("username", username);
    info.append("password", data.password);
    info.append("grant_type", "password");

    return axios.post(config.login, info)
        .then(response => {
            // Check if the authentication was successful based on response structure
            if (response.data && response.data.success) {
                // Authentication successful
                return response;
            } else {
                // Authentication failed, show a toast message
                toast.error('Incorrect username or password');
                return Promise.reject(new Error('Authentication failed'));
            }
        })
        .catch(error => {
            // Handle other errors if needed
            return Promise.reject(error);
        });
}