Auth0 code_verifier

Questions
1

So the auth0 verifier parameter never seems to work, I am generating it in this way:

function base64URLEncode(str) {
    return str.toString('base64')
        .replace(/\+/g, '-')
        .replace(/\//g, '_')
        .replace(/=/g, '');
}
var verifier = base64URLEncode(crypto.randomBytes(32));

Which is the same way the site uses and the normal standard for auth0:

https://auth0.com/docs/get-started/authentication-and-authorization-flow/call-your-api-using-the-authorization-code-flow-with-pkce

I am also unable to use a static code_verifier.

Error I always get:

{"error":"invalid_grant","error_description":"Failed to verify code verifier"}
2

Only two possibilities.

One as there will be really issue on site server side

Another as maybe the using some other method other then generating the random. Check there js to.