How to use the automatic exposure lock key of Canon eosr 10 camera?

Canon eosr 10 camera automatic exposure lock button. In spot metering mode, align the circular frame in the center of the viewfinder with the metering reference part, and press the button set as automatic exposure lock function. Inquire according to relevant information: automatic exposure lock/flash exposure lock button: when the shutter is half pressed for metering, press this button again to lock the exposure; When the built-in flash rises, focus on the subject, and then press the flash exposure lock to contact the camera.