Add the Teams URL field to the reservation page Layout and Reservation Form

To show the Teams URL field on the reservation form and the reservation record page, you need to take the following steps:

Steps:

Go to Setup - Object Manager and find the Reservation object.
Go to Page layouts - there drag the Teams Join URL field to the page layout and save.
Go to Field Sets - Add the Teams Join URL field to the field set that you are using on your reservation type and save.