Display battery percentage?

Show the battery percentage on your iPhone, iPad, or iPod touch - Apple Support

Yes. Slide down from the top right to open Control Center. That will show the battery level as a number.

You can also say "Hey Siri, how's your battery?" or just hold down the power button and say "battery."

You can see Battery Percent by dragging the Control Center down, from the upper right corner of the display. It is not possible to view it permanently, as there is no space due to the FaceID Camera.