What type of proof would you like? An official statement by Pakistani militias that the government asked them to do it? We see similar tactics being used in Syria by Al-Jolani / Al-Sharaa to wipe out the Alawaites (20-50,000 executed) with the same being planned for the Druze. That way the government can say "it wasn't us", although of course, they didn't prevent it.

Proofs have been provided in lot of previous terror attacks like 26/11 Mumbai attack, Pathankot, Pulwama etc. What did Pakistan do with the proofs? Nothing.