VPN connection to Cisco ASA 5555 from Ubuntu 20.04 server using IPSEC and StrongSwan

I am looking for an experienced freelancer who can help me set up a secure VPN connection between my Ubuntu 20.04 server and a Cisco ASA 5555 device. I do not have access to the Cisco ASA 5555 device, and have no control over the settings on that side. I do have the IPSEC and StrongSwan software already installed on Ubuntu 20.04 and some experience setting up this type of VPN connection, but am out of my league with this one and don't even know the right things to ask the team that handles the Cisco ASA 5555 and their setup. They claim this is a site to site VPN and IKE2 using PSK. They wanted to know what "interesting traffic" would be used and other things that I don't know how to configure on our side. The freelancer must have the ability to properly configure the connection to ensure proper security protocols are followed. Must be done through our Ubuntu 20.04 server we already have set up. If there is something better thanStrongSwan to make this happen, we are open to using that. The person must be able to communicate with the other company to gather the information needed and to relay information about our setup to them as well.