I want to connect a GSM 800L V2 5V module to an ESP32, but during my research, I couldn't find a reliable wiring guide. I need a safe solution that won’t damage my ESP32.
What have you determined is "reliable" and "safe" (maybe easier, what is "un-safe" and "un-reliable")?
A simple Google search turned up lots of hits. I suggest you look at the Last Minute Engineers site.
How did you determine this? If you know that it is not reliable you could possibly modify it so it is.