Wordpress plugin - can't find admin api key

Hello, I take the discussion and have a question : I have a discourse site and a Wordpress site, the differences between the Api key for all users and only one is :
All users ; all users could see and interact with both discourse and Wordpress
One user means that when connected this user only can interact with both wordpress and Discourse.
Am I right ?
What is the risk to generate an all user Api key and giving all permissions ?
Thanks