Board Thread:General Discussion/@comment-31437237-20170322152533/@comment-26900200-20170322152913

Well usually, in the top right corner there will be an option called "Create Party Link" or something along the lines of that. Just click on that and a URL will appear. Copy and paste it into like an email or however you'd like to communicate and tell them to click and go to said link. Then that should allow all three of you to play on the same sandbox server together.

Hope this helps :)