Hello Greetings Doris
Problem because facebook has changed permission.
Please help me find and open file: administrator/components/com_joautofacebook/libraries/base_facebook.php and go to line 524 in function "getLoginUrl" and help me add a line
$permission[] = 'publish_pages';
And
And in component please delete old account and create new account again and connect to facebook
Or you can send me joomla administrator and facebook accounts via contact form? So we can help you update and config again for you
Best regards
Bach Pham