You will enhance the existing APIs by adding four new APIs—sign-up, sign-in, sign-out, and a refresh token. Sign-up, sign-in, and sign-out operations are self-explanatory.
The refresh token provides a new access token (JWT) once the existing token expires. This is the reason why the sign-up/sign-in API provides two types of tokens—an access token and a refresh token—as a part of its response. The JWT access token self-expires, therefore a sign-out operation would only remove the refresh token.