Hey, those basic lands are from the Ixalan Standard Showdown. PSS2 is the set code and it's not a valid set code on this site therefore you can't add a variation of the lands. I searched the alters for each one and found them.
Alters (Plains and Swamp don't show up, but these are the correct alter codes. Ask someone that works at this site about this problem):
Forest *A: 16210* *F* Island *A: 16207* *F* Mountain *A: 16209* *F* Plains *A: 15427* *F* Swamp *A: 16208* *F*
The same basics lands were used in Commander 2016:
Forest (C16) *F* Island (C16) *A: 8011* *F* Mountain (C16) *F* Plains (C16) *F* Swamp (C16) *F*
If you would like to make your own alters of each land you can find high quality images of the PSS2 lands here