BuddyPress.org

Please don’t bump your own thread three hours after your initial post. 24 hours is a good duration before bumping again.

As for your question, set the WordPress default role to “Contributor” (https://codex.wordpress.org/Settings_General_SubPanel) and the member should be able to post. Though your member will have to use the WordPress dashboard to post, unless you use a front-end posting plugin.