I integrated a simple bot to Facebook messenger. However it's only responding when I messege from one of my accounts When i try to messege from a different account, it doesn't respond. Can someone explain why? Also is it possible to have bots with Single Choice questions in messenger and Instagram?

I had the exact same problem. Lmk if you find a solution

The issue is that there is an approval section through permissions you need to seek approval from to receive permission for others to message you. It's a tedious process but there are companies that bypass this, just trying to find out how.

☝️ what Islam said. In order to go public, and FB apps (like bots) have to go through a manual approval process. In the mean time, you can add up to 5 test accounts for other people to test. But for public use you have to get approved. https://developers.facebook.com/docs/app-review/submission-guide/