AuthenticationException: The remote certificate is invalid because of errors in the certificate chain: UntrustedRoot, NotValidTime

In my case, my domain's SSL certificate has expired. So, please check your domain certificate expiry date. The solution is to renew the domain certificate.

Temporary solution: Skip SSL certificate validation.

var handler = new HttpClientHandler();
//handler.ClientCertificateOptions = ClientCertificateOption.Manual;
handler.ServerCertificateCustomValidationCallback = 
    (httpRequestMessage, cert, cetChain, policyErrors) =>
{
    return true;
};

var client = new HttpClient(handler);

Ref.: https://stackoverflow.com/a/46626858/672891

First enter these two commands

dotnet dev-certs https --clean
dotnet dev-certs https --trust

Then delete all the files in this path:

C:\Users\{User Name}\AppData\Local\Google\Chrome\User Data\Default\Local Storage\leveldb

Delete your offending localhost certificates:

Control Panel -> Internet Options - > Content tab.

1. Click Certificates and remove the ones you no longer require.
2. Click the Clear SSL State button.

Follow instructions here to recreate new certificate for each of your localhost sites, paying attention to the port number:

https://improveandrepeat.com/2020/05/recreate-the-self-signed-https-certificate-for-localhost-in-iis-express

Other thing that can be done in case you need it for local development and the server itself has issue with the certificate like it being issued by a root that is not common or not trusted by your machine. You can go to the website and follow these steps":

After downloading its root (i downloaded the whole chain but i supose only the root is needed) you can then install it and add it to your Trusted Root Folder by opening the downloaded certificate

Not sure if that is safe to do but if you are working with websites that are owned by a secure source I suppose it's okay. Also I suppose that is all possible to happen on only non-prod envs, but still like other solutions I suggest not depending on it on prod. Not sure if it's even doable on non-local.