Understanding the menu is key to using the button for configuration. Each set of menu items and value is represented by a red flashing light(s) followed by blue flashing light(s). The red flashing light and the number of flashes it makes, indicates where you are in the menu. The blue flashes of light indicate the current value of the menu item you are on. The image below shows the menu options and possible values.
To change the value of the current menu item, quickly press and release the button. To change to the next menu item, press and hold the button for 3 seconds and let go. The red light will flash to let you know what menu item you are on and the blue light will flash to let you know the current value.
To unlock you must be on the band menu item. Press the button for 3 seconds and let go to enter the menu navigation. You are now in the channel select menu. Press and hold the button again for 3 seconds. You are now in the band selection menu. Now hold the button down for 30 seconds and let go. The red LED will flash 3 times to confirm. The image below explains this process.
To confirm your VTX is unlocked after it finishes booting, it will show a constant BLUE LED for the locked state, and a constant RED + BLUE LED for the unlocked state. If both RED and BLUE LEDs are showing, your VTX is unlocked and you can change to one of the yellow bands in the TBS Unify EVO frequency table below: