TBMK You will need to Download the photos from Account A, and then re-import the photos to Account B.
There is a suggestion in this forum link to do this using an Export method.
Or I believe you could use the Downloader App that may be easier.
DOWNLOAD CLOUD PHOTOS
(edits made to the raw images are written into the XMP sidecar files that accompany the downloaded raw files.)
Regards. My System: Lr-Classic 12.3 Photoshop 24.3, ACR 15.3, Lightroom 6.3, Lr-iOS 8.0.8, Bridge 13.0.3, Windows-11.