Remove untrusted certificate notification

Hey there mon243,

It sounds like you're seeing an untrusted certificate notification on your iPhone and I'm happy to help.

Is this a managed device through an employer or a school? This article can help.

Trust manually installed certificate profiles in iOS and iPadOS

This article will walk you through removing the notification pop ups by viewing and responding to those notifications:

View and respond to notifications on iPhone

If you wanted to change your notification settings you can do so by following the steps in this article:

Change notification settings on iPhone

Hope this helps!