How correct is it to send customer and administrator data over one REST interface?

Question

RESTful API

There are two user groups.
1. Admins
2. Clients
Designing RestAPI. I can not understand how to give user data. If everything is clear with users. /users/:id
When admins log in to get information about them, what address should I contact?
If the tables are different, then it seems that the IDs will be different. knocking on /users/:id is not correct.
On the other hand, you can, for example, access by the name /users/:login but also some not very good option. How to do it right?
There will simply be two types of users. Clients and customers.