Press and hold the key and then move the cursor to select the video on the page to open the picture-in-picture function.
Press and hold the corresponding shortcut key, then move the cursor to select the video on the page to open the picture-in-picture function.Hold down Alt/Option and move the cursor, the element where the cursor rests will draw a border, if the border is green, press the P key again to start picture-in-picture mode.