This JSON Web Token Security Cheat Sheet[1] or this python script[2] are both quite useful when reviewing anything using of JWTs.
[1] https://assets.pentesterlab.com/jwt_security_cheatsheet/jwt_...
[1] https://assets.pentesterlab.com/jwt_security_cheatsheet/jwt_...
[1] https://www.owasp.org/index.php/JSON_Web_Token_(JWT)_Cheat_S...