There's two issues here.
1) The lenses on the iPhone aren't long enough to shoot the moon as a primary subject. You typically use much longer lenses to do this, 200 mm minimum I'd say, but even better with 300 mm, 400 mm or more. The 2x lens on the iPhone is ~ 52 mm equivalent, but the iPhone rarely uses it in low light conditions, instead just cropping the 1x lens to 2x (because the 2x lens and sensor are much lower quality). So without the long lens, you wouldn't be able to see the details you want to see. I guess one of the only widely available phones to be able to do this would be the Samsung S21 Ultra.
2) As many others have said, the moon is bright, and you need to expose for it. If you have a long lens as described above, it'll already be closer to a good exposure. This is because exposure on cameras is usually just determined by the average of the scene. If most of it is dark, and the moon is small, the moon will be blown out (a bright spot with no detail). If you were to do this with something like the Samsung S21 Ultra, you'd still be best served by a pro mode or app, and the best image would be on a tripod with a longer exposure.
