Unable to calibrate accelerometers

I’ve read the other topics and answers, and the answers mostly depend on the terminal which has been deprecated to the point where it is not useful to get around the accel calibrate failure problem.
How can I calibrate my accelerometers? I hit the button, no response.
Using latest APlane and latest build for the Matek F405wing.
Pretty new at AP-- thanks in advance for help.
Jim Miller

Is your controller armed? You need to disarm.

and it has to be in manual mode