Prismarine Brick Slabs don’t work for /fill

Everywhere I look it says that Prismarine Bricks Slabs are stone_block_slab2 in the /fill command, but stone_block_slab2 is Smooth Red Sandstone Slabs, and Prismarine Bricks Slabs aren’t a subcategory of stone_block_slab2 like Prismarine Bricks are of Prismarine, Prismarine Slabs also aren’t shown