Those fixtures are designed to be cord and plug attached, so you'll have to install a receptacle where the existing fixture is. Since this is a garage, it will need to be GFCI protected.

What you should do is get LED shop lights that are designed to be hardwired. This is what I used:

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https://www.amazon.com/gp/product/B07TJ6WKK9/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

You can pull down the NM that's already in the box (if it's long enough) or pig tail a new piece and then use an NM connector on one of the knockouts i the box (I used one centered in the top of the thing, but there are ones on the end as well).