“ANVIL: Vault Breaker is a Roguelike twin-stick shooter from Korean developer Action Square. The game is currently in Xbox Game Preview and Steam Early Access, so naturally, it has some rough edges that will be smoothed out over time. One of those rough edges is that starting an online co-op game is clunky and confusing. Don’t worry; we’re here to help!” says Co-Optimus.
Source: N4G PC How to Play Online Co-op in ANVIL: Vault Breaker [Co-Optimus]