FlySky FS-GT3C Power Button
thingiverse
Lost my power button so I tried whipping up a new one. This just pressure mounts to the power switch which is just a ~2mm post rectangular post. Worked fine and seems to hold on using AmazonBasics PLA. Using another brand it was loose so YMMV. Also, this sticks out a little more that what I think the original did. I don't have an original to compare to so if someone wants to post exact dimensions and detailed photos in the comments that would be great. For printing, make sure you lay it flat on the front of the button. Update 3/1/19 - I added a second version that I believe is closer to the original (this is the one in the picture).
With this file you will be able to print FlySky FS-GT3C Power Button with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on FlySky FS-GT3C Power Button.