Open Arc's Keyboard Shortcuts
Go to Arc > Preferences / Shortcuts in the Mac Menu Bar
Or, hit Command-T and type "Open Shortcuts"
Customizing Keyboard Shortcuts
Open Shortcuts in Preferences (see above)
In the search bar, type the shortcut (e.g., "cmd d") or name (e.g., "pin tab") of the key binding you want to customize
To delete the shortcut or reset it to its default, right click on the shortcut:
Choose to prefer website / prefer Arc
In some cases, websites may want to use an Arc shortcut. In a case of conflict, you can choose if you'd like the website to take priority,
If you 'd like websites to win in a conflict, hit "Prefer Websites"
If you'd like Arc to win in a conflict, select "Prefer Arc"
You can also choose to "Notify me when shortcuts are conflicting" which allows you to hit the shortcut a second time to activate it in Arc.