See this article: Where do I access the Accommodations tool?

When you set up your hotel room blocks, the hotel will provide to you a URL link to their webpage that is configured for your event.  There are 2 ways to use the URL you are provided.

1. Room Reservation URL - paste the URL they provide into this field
2. URL Shortner - paste your URL into this field and click the Shrink URL with Bit.ly button - doing so will put a shortened version of the hotel's URL into the Room Reservation URL field automatically

By default, room blocks only display on the Confirmation Page (the Thank You for Registering page). Optionally, you can set them to display on the registration page.  However,  this is not recommended because a registrant may go to the hotel page while in the middle of registering and forget to come back to complete their registration.