I need advice on how to restore the frequently used page which used to appear when I opened by FP1U.
It’s a widget. Open the Edge Swipe Menu, tap on “all apps” (the circle with the 6 dots), tap on “widgets” and drag the widget “Your apps” (in some versions it could also be named “My apps”) to an empty homescreen.
It is a widget. You’ll find it here: All Apps > Widgets. It is called “Your apps”. Tap and hold it and drag it to an empty screen.
Edit: @Irina_Spitznagel was faster!