In the doc it says get notifications from Webex App in "Windows 10: Settings > System > Notifications and actions"
https://help.webex.com/en-us/article/5wy2h0/Webex-App-|-Smart-notifications-on-multiple-devices
I think this option is to turn on all notifications ,and there is no "webex" on Notifications and actions page.
The customer is concerned that he just wants to turn off the notifications of webex only.