Cutting out complex shapes can be time-consuming, and on a curved surface it can be almost impossible to get right. Luckily, there's a tool called knife... | By Blender Secrets | In
How To Use The Knife Project Tool in Blender 3.0.0 - YouTube
Knife Project — Blender Manual
Knife Project — Blender Manual
Problem with knife project tool: the result is not smooth - Blender Stack Exchange