Setting up login credentials for OPEN VPN

[ADOZ]

Hello,
I have a Nighthawk R7000 rooter with a default OS (which I can't change).
I have for several years activated the vpn service with open vpn which works very well.
However, I'd like to increase security to connect to my rooter (and therefore to the connected nas server): set up a login and password connection.
Is there a (simple) solution for this type of connection via open vpn?
Is it possible to give rights to certain identifiers or remove them?
I'd like to stop distributing the identification key, but to grant connection rights.

Thank you in advance for your reply.

[boblewis]

To increase security on your Nighthawk R7000 router and NAS server:

Set up a login and password for router access.
Configure OpenVPN for user authentication.
Assign user permissions on the NAS server.
Stop distributing identification keys and use username/password authentication for VPN access.