Help of alpha channel in photoshop.

This paper lists two methods of loading and selecting alpha channels. The first method is to click the alpha channel and then load the selection according to the method. After loading the selection, you must click back to the RGB channel for other operations (that is, switch channels back and forth), otherwise you will still operate in the alpha channel.

If you hold down the CTRL key and click, you can directly load the alpha channel selection, and then proceed to the next step.