。
Don't forget to include me in the group.
Literal
Not-forget-[without-ず] group [dat-に] include-[give-me-てくれ]
くれ is the plain imperative of くれる ('give to me/us'), making ~てくれ a blunt masculine request: 'do X for me'. Softer forms include くれよ, くれない？, and くださる/ください. The listener's action benefits the speaker, which is what くれる encodes.