2.1. Send image/sticker

Facebook does not allow API app to send images via Inbox or multiple images at the same time through user comments to avoid the possibility of image spam. So to be able to send images to customers via inbox or multiple images via comments you must download the Pancake extension to be able to send.

Click on the following link, click Add to chrome, then on the pancake tab press Ctrl + Shift + R to reload it (note the extension only supports on Chrome and Coc Coc)

https://chrome.google.com/webstore/detail/pancake-v2/oehooocookcnclgniepdgaiankfifmmn