HOW TO CONFIGURE A JWT CONNEXION ON APP
Prerequisite you have to get the public key (format must be of Base64 encoded public X.509 certificate) associated to the provate key you'll use to sign your JWT bearer
Open (EDIT) your application from MyAPPlication in the user profile and copy / paster this public key

Save and the public key should be displayed as follows
Your application is configured to retreive a token with JWT assertion