Lubricate O-ring and Apply Teflon Tape

What happens here

Before reattaching the tub spout, apply silicone grease to the existing O-ring on the brass pipe extending from the wall. This ensures a good seal and prevents wear. Next, apply Teflon tape (also known as PTFE tape or plumber's tape) clockwise around the pipe threads to further enhance the seal and prevent leaks. Ensure enough tape is used to cover the threads completely but not so much that it interferes with screwing on the spout.

Goal: Prepare the pipe connection for a watertight seal