You cannot customize the list view item's actions. Actions in Lightning Experience mention this:
List view items support only specific standard actions, like Edit,
Delete, or Change Owner.
There's a couple lowly voted ideas asking for this ability:
You can customize the buttons that display on the list view itself. This would allow you to select one (or multiple) records from the list view and perform an update action on them (quick action) or pass the record ids to a flow (through URL button) or VF page.
- Create a quick action of the type
- Add it to the list view layout
Setup --> Object Manager --> Your Object --> Search layouts for Salesforce Classic --> Edit "List View" layout
If you need more complex logic to be initiated by the button (multiple screens) or to leverage a LWC, you'd have to look at utilizing it within a Flow or a VF page in a List Button that has
Display Checkboxes (for Multi-Record Selection enabled.