Facebook Lead Form Workflow stopped working

I created a workflow integrating facebook lead ad form and Wati for automatic whatsapp communication whenever someone fills up the form. It was working fine till yesterday but today it is not working anymore. Not able to track the reason for it. Attaching the photo of the workflow.

Attachments

Moreover, please tell how can we track which step in the workflow is problematic and disruptiing the whole workflow.

Hey @yourrevealedpath

Error validating access token: The session has been invalidated because the user changed their password or Facebook has changed the session for security reasons.

As we can see from your recent tasks history, it seems like you have changed your Facebook account's credentials and because of that, you are not getting the leads.

Thanks