Add transit card to kids managed Apple Watch.

My kids 12 and 14 both have managed Apple Watches and the city gives students discounted passes. They have a card but I would like to add the pass to their Apple Watch. I can add a transit pass to my own wallet just fine, but haven’t found where to add the pass. When we try to add a pass on the phone we get a message that says “Unable to Add Transit Card. Ask a parent or guardian to add one for you.” Which would indicate there is a way to do this. Feels like there should be a simple “add existing pass” feature or a way to “add to wallet” from the transit provider. Anyone have any luck with this?