I took so much searching and effort for me to figure this out, and I found a solution that works for me. I made this account because i suffered so much going through outdated Facebook/Meta documentation I want other not to suffer the same fate:
I had it working months ago with user access tokens with the publish_to_groups permissions and an app installed in the group to give those permissions. That stopped working a while ago, and I could not figure out how to do this.
IMPORTANT: I have a verified business on Meta, and I think this could be necessary for this to work (see business_management permission)
Posting to pages is still working fine, where you need to make a page access token (instead of a user). It turns out that you can actually use the page access token to post in groups for which a page is an admin. Yes, for some reason, Pages can me members of groups, and even admins of groups, and if you post to the /groupid/feed with a page acces token, that works! At least for me.
So these are the steps:
Create a new page (I had already had a Page up for my brand with a Page access token generated)
Switch to your Pageās profile in facebook
Join the group you want to post to. If your group is public, its easiest to request joining from the Pageās side. My group was private, so I needed to create a invitation link (cause you canāt invite Pages, only People) and open that link when logged in as the Pageās profile.
Approve the join, from both sides if necessary (a lot of switching between Page profile and the profile in chareg of the group happening here)
Make the newly added Page member of your group an admin of that group.
If not done already, create a Page access token in the graph api explorer with all of the following permission:
pages_show_list
business_management
page_events
pages_read_engagement
pages_read_user_content
pages_manage_posts
pages_manage_engagement
The Business managemtn one is important, even for posting to your Page, cus I could not get to see the list of Pages in the Graph Explorerer until I added all these permissions. I also selected "All businesses and all pages when connecting after clicking āgenerate access tokensā because making subselection did not work out. I tried so many things at the same time that I donāt know if all or only some of these things are required, but Iām not touching it anymore.
Maybe quickly test if you can alreayd post to your Page with the page acces token.
In your code where you were posting to /groupid/feed, change the user access token tot eh page access token, and that worked for me.
I hope I didnt forget any steps, cus it was a very chaotic experience. Hope it works for you as well! The cool part is that you post as your brand in the groups page,instead of your personal facebook account, so thats neat.
If not done already, create a Page access token in the graph api explorer with all of the following permission:
Would you be able to explain in greater detail or point me to a guide? My understanding of the Meta App world is extremely limited and canāt seem to find āCreate a Page Access Tokenāā¦ plus I had to create an App, not sure if Iām on the right track.
Unfortunately, a few days after this worked, it stopped working. I was able to make 1-2 posts, but then some days later, this route was also blocked. I have not found a solution, sorry.