I was able to populate the default date field via plugin folder > inc > widget-frontend.php, designating the value for the <input name="startDate"> element
I think what he means is how can a user follow without the fb page opening and having to click “follow” there. Just click follow on the website and its done
do you still have the old site, you could try deleting the new site’s database and directory, and re-migrate using wp-duplicator plugin (super easy migration)