I need to update a person field in a list using a result from a people search (sourceid=B09A7990-05EA-4AF9-81EF-EDFAB16C4E31). The search works great, but does not return the person's ID that I need to use to update the person field in the list.
I know I can get the ID for site users using the /_api/web/siteusers REST endpoint (and have implemented this successfully), but I need to be able to get the ID for any user in the tenancy, not just this site's users.
Any help would be greatly appreciated.