XF 2.1 Problem with conversation API

[Miacommunity]

I have a problem to use message API for my mobile app, integrating private message and mobile conversation.
Now I have integrated login/signup, implemented message scenario, get contact list
By the way, when I call message api to get messages with other users, I got error that permission deny.
How can I fix this problem?

Thank you.

 

[Paul B]

As previously communicated, the development forum is the correct place for questions of this nature.