Trouble Calibrating ESC because of Initializing APM

I can’t calibrate my ESC because of the rainbow signal light it should be blinking yellow right to calibrate my ESC but this signal light it stopping me from calibrating my ESC because I don’t know what happened what should I do to fix this error. but whenever I connect my drone to mission planner the Message log saying “Initializing APM” it won’t appear again but I try it again it goes like again and again. i research some related problem that I’m having and it still doesn’t work. still having the error.