Walk in clinic for exam?

The clinic my DS is assigned to for the medical exam told him it is just walk in for that kind of appointment, no appointment necessary. They did look up his name when he called so he is in their system.

Has anyone else had a similar experience?

Do we put the date we plan to go into the DODMETS system?

Also, the clinic is two hours from us. We are in a rural location, so I’m sure that plays into it.

Thank you!