Cannot Give minecraft:end_portal

I wrote the commands "/give Peekofwar end_portal", and "/give Peekofwar minecraft:end_portal", but they give the same error. Apparently the item does not exist, even though the game identifies the blocks under the exact ID "minecraft:end_portal".

I seem to remember this being a thing in previous versions of MineCraft as well; it's not just 1.11.2.