How to setup third party l2tp server on pfsense?

Question

pfSense

Hi all. There is a provided third-party l2tp server, which was provided with all the credits and the key. Through it, you can go to a certain service, but the Internet is lost. How to set it up on pfsense so that you do not need to connect to a third-party vpn, but write rules on pfsense. Or at least so that the Internet is not lost. I will be glad for tips))