BFT MITTO 2-button remote control 433.92MHz is the most popular BFT Mitto remote control model sold in market, please refer to following document to find how to program BFT Mitto to RIGEL 5 radio receiver board.

Programming BFT Mitto to RIGEL 5 Board Instructions

If you have a RIGEL 5 board with screen, go into the Menu by Pressing OK.

Select RADIO by clicking the + and then clicking OK on RADIO.

Click ADD by pressing OK.

Press OK again. it will say Secret button, press both buttons on the remote at the same time. then press the button you want to use. Press + and - at the same time to exit the radio menu, and again to exit the main menu.  

Or if you have a CLONIX Reciever, use the following instructions online -

If you have no secret button on the back of the remote, where it says press the secret button - instead, press both buttons on the remote control together.