How to make an external static ip on a TP-Link 3420 router?

Question

openvpn

The task was given as follows: to make an external static ip on the TP-Link 3420 router. The Internet comes from a modem from Yota. I can replace the router with Zyxel Keenetic 4G.
A static ip is needed to access certain sites, where, in addition to the login / password pair, there is also a binding to ip. We are currently using the free Kebrum software. Willing to pay a small amount for openVPN or something like that. Priority is that the solutions are free.

Answer 1

If you raise vpn, then the statics should be from the side of the vpn server where the connection goes, you need to look for services where they can give a static IP at the output, but then what's the point in vpn