You cant, you can only get season rewards from the season before current, the one before the current season was splinter the fallen one where yoy grab motes an fight in the matrix, the only was the aquire the season pass gear is if you unlocked it an didnt claim it. I.e if you only got to season pass lvl 50 from season of the splicer you can only claim rewards up to lvl 50 that you didn't claim on during the season. The cabal season is 2 season ago an no rewards can be claim.