Albums in Google Photos cannot as such be transferred to another account. You must add the photos to a new album in the target account.
Notes:
Descriptions, modified dates or added locations are also transferred.
All edits (added text or locations, sorting) done in the original album are lost.
By adding the photos to an album, they are also automatically added to the Photos tab (if not already there). Photos that were already on the account will not be added again, but will still be added to the album. That allows to transfer albums also after all photos have already been transferred, for example by Partner sharing.
The procedure is as follows:
Open the album in account A
Check 3-dots > Options and turn "Share photo location" ON if you want to transfer also the location.
Click in the share icon and either Create (and copy) link or Copy the existing link
Open the link in account B
Copy the album title
Select all photos in the album (see how to Select multiple pictures)
Click on + (Add to) > Album > New album
(on mobile devices, tapping on Album immediately creates a new album)
Paste (or type) the album title in the title field, and click on v (Ready)
Click on 3-dots > Options. More options appear when you activate to share by link.
Select or deselect the options you want.