L2TP/IPSec VPN on Debian 10 without Network Manager

I have 2 computers - both on Debian 10. I need to connect them both to the same remote VPN server. One has a desktop manager (with Network Manager), and the other does not. I will refer to the one with the desktop manager as Debian GUI and the other as Debian Server.

I have successfully connected Debian GUI to the remote VPN server using Network Manager, however I am stuck unable to connect Debian Server to the remote VPN server.

Here are the Network Manager settings, with details modified for privacy:

i.sstatic.net/S8pAI.pngi.sstatic.net/ZAeMI.pngi.sstatic.net/FASRX.png

These are the only settings I used in Network Manager, and I am able to successfully connect to the remote VPN server on Debian GUI. However I have been unable to do the same on Debian Server. In Debian Server I installed strongswan and xl2tpd. I don't care which client I use as long as I can get it working, these were just the ones I found available in Debian 10. I attempted to configure them like so:

Let me know if any files needed to diagnose this issue are missing and I can add their contents here.

Then I started everything and got the following results:

Sources I used (I have tried a lot of combinations):

wiki.archlinux.org/index.php/Openswan_L2TP/IPsec_VPN_client_setupgithub.com/xelerance/Openswan/wiki/L2tp...onfiguration-using-openswan-and-xl2tpdmanpages.ubuntu.com/manpages/bionic/man5/ipsec.conf.5.html