I’m confused, didn’t you post this same game in the Unity forums as well?
Which engine are you using to build the game? You might want to include that information as I think the process flow for art assets is different between the two engines so you might get people taken by surprise if they ask to join your project and find themselves using a totally different engine to what they expected. You’re also looking for coders, and programming in Unity is completely different to UE4 (different language, no blueprints etc), so you might struggle to find the right people here.