I have just purchased this pair
https://www.aliexpress.com/item/1005003172817780.html?spm=a2g0o.order_list.order_list_main.35.65601802W6GwfD

At the LORA transmit end I will have an on/ off switch. Just need to make TXD high just using other pins, I dont want to hook up any serial input.

The send ...