I am using LoRa 32 v2 433mHz with external factory antenna.
In Germany at 433 mHz up to 10mW ERP (effective radiated power) are allowed to use without permission. 
In my application I´m sending data (only Numbers with two digits) with LoRa once a second from a sender device to two receiver devices.
How I have to set up the PA_Output to meet the 10mW ERP?
How does the antenna effect it? 
Does the spreading factor effect the calcultation? Up to now I´m using spreading factor 7, because the transmission should be fast and the distance is less than 100m.
Please help 