Verifying a JWT encrypted token with ASP.NET Core 5

Question

After scavenging bits and pieces from the net and trying to make it work, I gave up.

So here it is:

I have an OpenID token with a signature encryption of RSA-SHA256. I've tried the following code using JWT.net library

This is the token:

eyJhbGciOiJSUzI1NiIsImtpZCI6Ii11Zm0wSEVuMVpSbktHV2ZmQUttd0h0bEV4RSJ9.eyJzdWIiOiJhbG9uIiwiYXVkIjoiMTIzNDUiLCJqdGkiOiJMeVlDeGo4MzNEbHV3V2h0Q0s4OXZmIiwiaXNzIjoiaHR0cHM6Ly8xMC4xNDYuMzIuMTY0OjkwMzEiLCJpYXQiOjE2NDUwMjU4NjYsImV4cCI6MTY0NTAyNjE2NiwiYXV0aF90aW1lIjoxNjQ1MDI1ODY2fQ.KtS1WR3A61uSalUfrwbORx8AcYtsqudj9KlzFmf98W8PbwpSUu0axJmDYjHnH35ltYDjiZgX06RMKOSWQILt2O_4P2T1DtKUz0UOLjW04rpbz-pyOuw6sxQMHOQNUsUt_effojsBB6ISA6ejs-DKx652_M0JYMdZ_GnN2CODJdpZQIYI7xTgaOVrJjjzcxeczcMkGMTryS0qN8U4Pjy9Y4TAVTgSDw3Ca-dw-abwI4oY1aZILDEHglcCVcSMC5Vu6uO1BiLTD7Gc7wbMUi05OPxDrv4xumXVYVDpXhM4kENnoK3_gmGZMQ3SvFWAcFahwR-lyb8gisK8gZZ19PG-Iw

This is the latest code I've tried:

 string modulus = "w7Zdfmece8iaB0kiTY8pCtiBtzbptJmP28nSWwtdjRu0f2GFpajvWE4VhfJAjEsOcwYzay7XGN0b-X84BfC8hmCTOj2b2eHT7NsZegFPKRUQzJ9wW8ipn_aDJWMGDuB1XyqT1E7DYqjUCEOD1b4FLpy_xPn6oV_TYOfQ9fZdbE5HGxJUzekuGcOKqOQ8M7wfYHhHHLxGpQVgL0apWuP2gDDOdTtpuld4D2LK1MZK99s9gaSjRHE8JDb1Z4IGhEcEyzkxswVdPndUWzfvWBBWXWxtSUvQGBRkuy1BHOa4sP6FKjWEeeF7gm7UMs2Nm2QUgNZw6xvEDGaLk4KASdIxRQ";
 string exponent = "AQAB";

 try
 {
     IDictionary<string, object> claims = Decode(token, modulus, exponent);
}
catch (SignatureVerificationException ex)
{
     // signature invalid, handle it here
     return false;
}
return true;

private static IDictionary<string, object> Decode(string token, string modulus, string exponent)
{
    var urlEncoder = new JwtBase64UrlEncoder();

    var rsaKey = RSA.Create();
    rsaKey.ImportParameters(new RSAParameters()
        {
            Modulus = urlEncoder.Decode(modulus),
            Exponent = urlEncoder.Decode(exponent)
        });

    var claims = new JwtBuilder()
            .WithAlgorithm(new RS256Algorithm(rsaKey))
            .MustVerifySignature()
            .Decode<IDictionary<string, object>>(token);

    return claims;
}

I get the following error:

The signature is invalid according to the validation procedure.

Now, I don't really know what this modulus and exponent strings are. I just copied them from the example someone gave, so I don't know if it's related to my problem.

This code is also making no use of my secret key.

I did not generate the token myself. A 3rd-party authorization server is generating that.