Once you have an interview process guide created, there are three ways that you can make them available to candidates.
You can include a guide in your interview request to them. Upon the candidate accepting the request and getting introduced to you, it will become available.
After attaching the guide for a particular position once, that guide will be included with the next interview request by default.
A candidate can request an interview request if one is not readily available in the interview request. You will receive a notification if one is requested, in which you can send it by revisiting the interview request thread.