Can I reset my Retevis RT3?
There is no short key to make RT3 back to the factory default setting. If you want to reset the RT3, you need to get the factory default codeplug and write to the radio.
Download the factory default codeplug from here: https://www.ailunce.com/blog/Where-Can-I-Download-the-Retevis-Radios-factory-codeplug