How do i make a script which askes player for buying the gamepass on a gui?

i made a gui and checked some tutorials for making marketplacescervice on mousebutton1clicked on the gui but didnt work.

To sell a gamepass you should use PromptGamePassPurchase for example

local marketplaceservice = game:GetService("MarketplaceService")
marketplaceservice.PromptGamePassPurchase(game.Players.playerusername,gamepassid)

Replace playerusername with the players username and replace gamepassid with the gamepass id, If you don't know what your ID is, go the gamepass, look at the url, for this example the url is https://www.roblox.com/game-pass/1057151/Excellent-Employee. Now look at the numbers inbetween in slash after the gamepass and slash before excellent, that is the gamepass ID. If this solved your answer be sure to hit the checkmark next to my answer and if you still need help feel free to reply to this question with it!