Bienvenido a Platzi

//Using C# Net7
using Microsoft.IdentityModel.Tokens;
using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Text;

namespace PlayOauth
{
    public class JwtHandler
    {
        private readonly string secretKey;

        public JwtHandler(string secretKey)
        {
            this.secretKey = secretKey;
        }

        public string GenerateToken(string username, int expirationMinutes = 60)
        {
            var key = Encoding.ASCII.GetBytes(secretKey);
            var tokenHandler = new JwtSecurityTokenHandler();
            var tokenDescriptor = new SecurityTokenDescriptor
            {
                Subject = new ClaimsIdentity(new[]
                {
                    new Claim(ClaimTypes.Name, username),
                }),
                Expires = DateTime.UtcNow.AddMinutes(expirationMinutes),
                SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha256Signature)
            };

            var token = tokenHandler.CreateToken(tokenDescriptor);
            return tokenHandler.WriteToken(token);
        }
    }
}