If you have the glass plate (I couldn't tell for sure from the photo), then yes, you have everything.The Heated bed Flex Build Plate Stickers in your link are for an optional stainless steel flex plate that doesn't come with the Flashforge Adventurer 3 Pro.Glass gives a super smooth finish, where the sticker material on the flex plate will have a somewhat rough finish.Glass can sometimes be hard to get the first layer to stick properly without hairspray or glue stick, where as with the flex plate sticker things stick very well, and you'll need to flex the plate to get prints to release.Printing dice for example, with glass looks great. Printing dice on the flex plate leaves one side of the dice with a rough finish.Glass by far gives a better finish to the bottom layer, so you're all set to make super nice prints.