Why is my Facebook pixel ID different when creating an ad?

my pixel that is working in event manager, the id is not the same on my facebook page when i want to create an add, how do i change that? its changed on my shopify channel , but still says the other one on fb. how do i delete all the other pixels. Im finialy ready to start running ads now this! please help!!!

Log into your Facebook business manager at https://business.facebook.com/. From there, go to “Business Settings”. Click on “data sources” then “pixels” like this screenshot I just took for you:

Your pixels should be there and you can assign the right one to your ad account while removing the other. If a pixel isn’t there, it is under a different business account.

You can also try this tutorial for step by step

https://magecomp.com/blog/add-facebook-pixel-on-shopify/