"Flowing" song from Sonic Frontiers, Cyberspace Level 1-2. Enjoy.
Extract the folder from the archive to the "PayDay2/assets/mod_overrides".

Showcase (or, more correctly, hearcase) of one assault wave:
https://youtu.be/dFSpcYf9-rg

Inspired by Vinyl The Glaceon's Sonic Heroes OST mods