There are 2 types of Vrbo (formerly HomeAway) connection: API integration and ical. API integration allows you the full sync of your calendar and content related updates. Ical connection updates only availability.
For additional information about Vrbo integration and the process, you can check the following articles:
How does it work content related updates?
If you want to change some settings on the listing level, for example, maximum person capacity, please go to Listing > Edit > Basic info > Person capacity > change the number and save it:
The update will be synced in a max of 24h on the Vrbo channel (Only if you have API integration, not the ical)
How can I know which field can be updated?
You can click on the circle next to the specific settings and you will see the following:
If it is shows Connected, your update will be synced with Vrbo channel automatically.