Correct Size Of A Dev Product

I was making a dev product today but when it came to the image size, I didn’t know what to put. I looked online EVERYWHERE for it but I still couldn’t find it. I’ve tried 420 by 420 and a lot of others but what will fill the whole blank?

The image size for the gamepass is 150×150

No. Not for a gamepass. For a dev product.

420x420 pixels is the largest size here is also where you can find sizes if I wasn’t talking about the correct one: https://developer.roblox.com/en-us/articles/Game-Passes-One-Time-Purchases

I believe it is 420x420. Are you sure you’re exporting your image at that size?