For production, you need to have Secure Token Service (that is, a web service), which issues a JWT token upon an HTTPS request. For test, you can use the code shown in the GetTokenAsync method defined in Program.cs.
After a user is authenticated, the player makes a request to STS for such a token and assigns it as the value of the token. You can use the Azure Media Player API.
For an example of running STS with either a symmetric key or an asymmetric key, see the JWT tool. For an example of a player based on Azure Media Player that uses such a JWT token, see the Azure media test tool. (Expand the player_settings link to see the token input.)