From this article, it says
If the login URL that is configured in Security settings is https://awesomecompany.com/sso/jwt/login, then the redirect URL would be https://awesomecompany.com/sso/jwt/login?client_id=a13v13&state=hgdg43567&nonce=1545894408&grant_type=implicit&scope=openid%20email%20profile
Is it possible to add custom parameter when the authorisation url is being called, for example, adding a ‘uid’ parameter at the end,
It is more detailed here.