Add hotkeys to tools or menu items to allow quick access.

If you type a single letter, you can only use that hotkey when single key hotkeys are on (see Turn single key hotkeys on or off).
Paint hotkeys are listed in the section, near the bottom of the editor.
All the functions accessible through the menus of the are listed in the section.
See Windows > Editors > Canvas Layer Editor
.

However, you can map the rest of the function keys. Do not change any of the modify hotkeys. A modify key is a hotkey that involves a mouse click-drag-up in conjunction with pressing a key (for example, modifying the radius, opacity, or size of a brush).