they're pretty easy to make actually, if you know how to use them just do /summon interaction ~ ~ ~ {width:,height:} and if you wanna add a tag do /summon interaction ~ ~ ~ {width:,height:,Tags[""]}
They don't have extra stuff like rotations and transformation, block IDs, so it's easy, but you can also use a command generator like Mcstacker if it's too hard.
Sometimes you need to make your creations interactable, but there is no option to create interaction entities. It would be great to have these.