Scroll up and read my comment, there could be a discord group but it is just for team discussion not for investor therefore the group is closed
So why don't they give investors a discussion? as an investor of course also have the right to issue an opinion or ask something they want to ask, looks like very strange project

Have you never visited a website? They have provided Facebook, Twitter, and email to be contacted. If you think that's not enough, ask the OP for the team to add another, because only the OP can talk to the developer.