أحسن الله إليكم Shaykh, when making wudu in the shower, must I take a handful of water and wipe my body part with it or can I simply put my body part under the running water?

Ustadh AbdulAziz al-Haqqan

If you mean ghusl, then just being in the shower, rinsing, and breathing in and out water is sufficient. But if you mean wudu, then make wudu; even in the shower, make wudu.