How to get a post author params using API Call

Hi to all,

I’m building a membership site using the Ultimate Membership Pro (UMP) plugin, and I need to get the post author membership level.

I need this, because I need to hide parts of post contents about the post author level and not about the user level.

The UMP plugin give me an API Secret Hash and an example of url “ Secret Hash]&action=get_user_levels&uid=exemple_1” and what the action do and the params that it return:

Action name: get_user_levels

Params available:

User Id : uid

Return : A List of User Levels. (Array)

But I don’t know what I should do to use it and what I should do to get the List of User Levels.

Can you help me, please?