How to connect two Arduino's to two REYAX LoRa modules?

have a look at this post corrupted-packets-by-reyax-lora-module which used the RYL998

you could save yourself trouble by moving to a board which incorporates a microcontroller and a LoRa module, e.g. ttgo-lora32 , Adafruit Feather 32u4 LoRa, TTGO-Beam, Hiltec LoRa 32, The Things UNO, Adafruit RP2040 with RFM95, etc
this saves the problems of level shifters, jumper wires which give poor connections and intermittent faults, etc, e.g. see river level monitoring