BETOOLL A-Frame 2 Brackets Swing Set Bracket with Mounting Hardware (Green)

Or at minimum if it's just for swings get the Steel A-Frame brackets on Amazon. You just need 4 4x4 posts and a 4x6 (or sistered 2x6) and it made us a sturdy swingset since COVID. Basically these: https://a.co/d/041QcD3A