The Facebook Messenger app supports a connection of a bot that can then be used to receive and send messages on behalf of a designated page that belongs to the bot.
The following steps are necessary for the correct setup.
Log into Facebook, navigate to Facebook developer portal and click the Add a New App button to create a new app.
Once you create the app, you will be shown the Product Setup page. Select Messenger and click Set up.
Scroll down a until you see the Webhooks section. Click on Add Callback URL button. You will be prompted to fill in a Edit Callback URL dialog. The required values can be generated through Integromat.
Log into your Integromat account and create a new scenario. Add the module Facebook messenger > Watch messages as the first module to your scenario. Click the Add button to create a new webhook. Enter a webhook name and a verification token of your choice into the respective field. You will need this verification token later. Click the Save button.
Clicking the save button will generate an URL of the webhook. Copy this URL to your clipboard.
Go back to the Edit Callback URL dialog. In the Callback URL field enter the URL from your clipboard and in the Verify token field enter the same token that you entered in step 4. Click Verify and Save to save the dialog.
Now you have to generate an access token for the bot. Go to the Access Tokens section (just above the Webhooks section) and generate a token for the desired page by clicking the Generate Token button next to the corresponding page.
– Check the I understand checkbox and copy the token to the clipboard.
Once you have set up a connection in both directions, you can finish your scenario.
In order to test your application before publishing it, you need to set up roles for developers who will test it. For non-developer accounts, the app does not respond until it is officially released.
You need two Facebook accounts to test the app.
First account that creates the app (bot) and is the owner of the Facebook page.
Second account that is set up as developer and sends the test message to the Facebook page.
For more information on how to set up the roles see the official Facebook documentation.