can we use ldap authentication for vpn in netgear nighthawk x10?

Hello, 

We have a Nighthawk x10 router with the following specifications:

DD-WRT v3.0-r43334 std (06/04/20)

and has this firmware:

DD-WRT v3.0-r43334 std (06/04/20)

and kernel version:

Linux 4.9.226 #460 SMP Thu Jun 4 00:59:50 +03 2020 armv7l

And we have PPTP configured for vpn connections of remote users and they are using the same username/password.

We would like to know, if it's possible to use our directory service, to make all users use their credentials (username/password)?

We would like to know, too if we can limit or control traffic of those users, what they can do when connected to corporate network via VPN? example, only RDP protocol is permitted?

Thank you in advance,