module prevents content frome saveing

Problem/Motivation

Conetnt coudnt be dasaved anymoore because of wsod on node saveing.

'PHP message: Uncaught PHP Exception Error: "Class "Pusher\\Pusher" not found" at /var/www/drupal/web/modules/contrib/in_app_live_notification/src/Service/PusherService.php line 18', referer

Steps to reproduce

install module
create content
published content
see error.

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes