。
Make sure you're here by the appointed time.
Literal
Promise [gen-の] time [by-までに] here [to-に] without-fail come [purpose-ように].
Another duplicate with the adverb 必ず ('without fail') moved to a different position. Japanese allows adverbs to float relatively freely within the clause before their verb — 必ずここに, ここに必ず, both work. The placement choice is mostly about rhythm and emphasis.