Here are some tips to fix the Yocan UNI Pro fire button stuck.
1) Remove the tank from the battery.
2) Use a pair of tweezers or pliers to turn the firing stuck button counterclockwise a few times.
3) The button on your Yocan vape cart device should now be unstuck from the battery.
If your device still can't work, please contact Yocan support team at email@example.com