Hi @Mr.shahi,
Welcome to the Community.
To troubleshoot Salesforce Case feed comments not appearing as Facebook Page comments, ensure your Facebook app has the necessary permissions and check for API limitations. Verify that your Zap is correctly set with the appropriate trigger and action, and test both steps to confirm data is being pulled and posted correctly. Review Zap History for errors, double-check field mapping and monitor API rate limits. If issues persist, try re-authenticating accounts and share any specific error messages for targeted assistance.
Don't hesitate to reach out if you need further assistance.
Hi there, @Mr.shahi 
Just came across this and spotted that in your screenshot it appears that the Page Post Insights action has been selected which would be used to generate insights for a specific post, not post a comment on a Facebook Page.
There is a Create Page Post action but it wouldn’t add a comment to an existing Facebook post, it would just make a new post. I did some checking and found a longstanding feature request for the ability to post a comment which was previously discussed over here:
Since that’s seems to be what you’re after here I’ve added your vote for that type of action to be added which will help to increase its priority. We can’t give any sort of ETA on when it might get added, but we’ll definitely notify you as soon as it is!
Sorry to not have a more immediate solution to suggest here. As we’ve already got one topic linked to that feature request I’ll be closing this out so that folks can follow along with any updates on the feature request in a single place. For anyone that comes across this post and wants to be added to the feature request please reach out on the main topic here and we’ll be happy to add your vote to it!