So this is a sneeky was to annoy your friends or stop someone from entering a region you dont want players to enter
so the command is /give {usename} barrier , after placing down the barrier the blocks will go invisible after a while , these blocks cannot be broke in gamemode survival
i never knew about this block untill i searched on the creative list
as always if you found this tutorial helpfull be sure to leave a diamond and if you want any more tutorials be sure to leave them in the comments section below