shower walls

I am installing this shower kit and realized that I should not have primed and painted the mildew resistant drywall, but that ship has sailed. https://www.lowes.com/pd/DreamLine-Infinity-Z-White-3-Piece-36-in-x-60-in-x-79-in-Base-Wall-Door-Rectangular-Alcove-Shower-Kit-Left-Drain/5014370029...

I'm going to installing this Delta shower wall set in a remodel project: https://www.deltafaucet.com/bathroom/product/B67311-4834-WH.html#undefined It's a direct-to-stud wall set. The instructions show to use "adhesive" to bond the back and side walls to the studs (in addition to screws)...