Generate token JWT C#

GenerateToken.cs

private string GenerateJwtToken(IdentityUser user)
    {
        // Now its ime to define the jwt token which will be responsible of creating our tokens
        var jwtTokenHandler = new JwtSecurityTokenHandler();

        // We get our secret from the appsettings
        var key = Encoding.ASCII.GetBytes(_jwtConfig.Secret);

        // we define our token descriptor
            // We need to utilise claims which are properties in our token which gives information about the token
            // which belong to the specific user who it belongs to
            // so it could contain their id, name, email the good part is that these information
            // are generated by our server and identity framework which is valid and trusted
        var tokenDescriptor = new SecurityTokenDescriptor
        {
            Subject = new ClaimsIdentity(new []
            {
                new Claim("Id", user.Id),
                new Claim(JwtRegisteredClaimNames.Sub, user.Email),
                new Claim(JwtRegisteredClaimNames.Email, user.Email),
                // the JTI is used for our refresh token which we will be convering in the next video
                new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString())
            }),
            // the life span of the token needs to be shorter and utilise refresh token to keep the user signedin
            // but since this is a demo app we can extend it to fit our current need
            Expires = DateTime.UtcNow.AddHours(6),
            // here we are adding the encryption alogorithim information which will be used to decrypt our token
            SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha512Signature)
        };

        var token = jwtTokenHandler.CreateToken(tokenDescriptor);

        var jwtToken = jwtTokenHandler.WriteToken(token);

        return jwtToken;
    }