Downloads can be found here (1.21.4):
https://modrinth.com/datapack/ben-10-unearthed
https://www.planetminecraft.com/data-pack/ben-10-unearthed/
https://www.curseforge.com/minecraft/data-packs/ben-10-unearthed
This datapack is also available as a fabric mod, which can be found both on Modrinth and CurseForge here:
https://modrinth.com/datapack/ben-10-unearthed
https://www.curseforge.com/minecraft/mc-mods/ben-10-unearthed
Map used in the trailer (City of Newisle): https://www.minecraft.net/en-us/marketplace/pdp?id=40c35d26-f87a-49c5-9626-abd1695bae9a