If you are referring to the Invitations of the Nine, then you need to wait until tomorrow. When Sure shows up, you need to visit him, and then purchase the invitation he offers at the bottom of his vendor page. Read the invitation text fully to know what to farm, and WHERE to farm it. While the quest won't disappear at weekly reset, you want to finish each weeks Invitation before the following Thursday reset. Failure to do this may prevent you from obtaining the next Invitation the following week.