To enroll a new foster parent in your foster program, go to the Processing > Attributes tab on their person record and select the "Willing Foster" attribute. You can set their initial preferences, capacity, and blackout dates. The foster parent will receive an email with a link to update their profile anytime.
For more information regarding the foster portal from a foster's point of view, take a look at this article.
You can also access their foster profile from their Animals tab:
You can then use the Foster Finder feature to search for and contact all of the available fosters that fit your needs at any given time. Learn more here: How does the Foster Finder work?