Export Photoshop keyboard shortcuts custom presets from an iMac to import them from a Macbook?

The presets are about the various preset panels, such as Gradients, Styles, Patterns, etc.

The keyboard shortcut settings are in a totally different place. You will find them in:

 /Users/[USERNAME]/Library/Preferences/Adobe Photoshop 2022 Settings/Keyboard Shortcuts.psp

Just copy that to the same location on the other Mac.

If you made custom workspaces or some other custom settings, you’ll find them in the same Settings folder.

For future reference:

Preference file functions, names, locations | Photoshop (Adobe support article)

The keyboard shortcut settings location is listed in that article.