Posting to a specific forum, how?

If you go to https://community.adobe.com/    You will see this page.

Change the Sort order from Popular (Popular to who) to Alphabetical, as shown in the Red boxes in my screen shot above, then scroll down until you find the program specific forum you want to ask a question about (which will be much easier to find as they are listed in Alphabetical oder now instead of Miss Mash of whatever a popular forum list is) and then Click on that program name. You will see a forum page similar to this.

Click the "Post To Community" button, Red outlined and red arrows point to it in my screen shot above, in the upper sight hand corner.

Please Note that you have to be Signed In with your Adobe ID to do this.

How were you able to post to this forum?

This uses the exact same forum platform as Lightroom for Mobile.

Are you sure you signed-in with your Adobe ID and password?

Make sure you are signed in and go to the forum from here:

https://community.adobe.com/

Then click on the Post to the Community button on the top right.