In order to stream to a scheduled event on Vimeo from Studio, you need to follow the steps below in order for the event to appear as an option in Studio.
First, in a browser, go to your Vimeo account and create a live event. Vimeo allows you to create either a one-time event (only go live once) or a recurring event (which you can go live to repeatedly).
After setting the title, time, and audience, you will be brought to the event setup page and your event is available to select from in Studio. There is no need to click the "Next" button on this page, especially if your event is more than 60 minutes away.
Launch Livestream Studio and navigate to the Stream tab. Select Vimeo and log into your Vimeo account.
Under the Stream tab, open the Select Event menu. Your event should be listed here. The rest of configuring your stream is the same as streaming to a new event.
When you are ready to start your stream, click Go Live in the bottom right corner.