Why does iOS ask to “allow” Dumb Phone to open apps?

When opening a specific app the first time via Dumb Phone, you might see an alert asking you to "Allow" Dumb Phone to open it.

This is due to the privacy design of iOS where apps don't know of each others' existence.

In this scenario, Dumb Phone is simply asking iOS to open another app, in which iOS acts as a mediator asking you to confirm this action, and then allow iOS to proceed with opening that app.