For those of you who want an extremely simple build, I've reduced it to just 5 parts: one 1-megaohm resistor (0805 SMD) one Arduino Pro Mini one Ra-01 LoRa module Male header pins Battery clips See photos.

@evb - correct!

@benhub - ok, there are some things you need to consider, and that is the space of the adapter. I read now i "suggested" this adapter, but let me clear it it is not tested, maybe a language barrier from my side. You need to consider that it fits in the board and do not crash into other compontens, like the arduino. If it does, you maybe need to consider some other board or even build one.