This information is for the Builtober 2021 event and server.
You will be able to enable JEI cheat mode. JEI is the menu that shows you all the available items and blocks that you can use. To enable JEI cheat mode, press CTRL & left-click on the wrench next to the search bar.
It will turn red, and you will be able to click on the items in the menu to put them in your inventory.