Meet them at the door every single time they go to leave and remind them that you’re counting on them to come home safe to you. Do it again when they come home and thank them for cooperating with your earlier request.
If you can’t get to the door, call them to your bed or chair side. Face time them. Text it. Put a note out. (This doesn’t imply leaving a post-it-note up and letting it be the permanent message deliverer unless that’s genuinely necessary.)