Your information may be out of date. Wiki[1] says "In December 2021, the FDA approved Apretude, which is an injectable form of PrEP", and Apretude seems to be a brand name for cabotegravir, which is the chemical named in the OP. (The capital letters in PrEP make me think it's a specific drug, but apparently people use it to mean several different drugs with similar purposes.)
PrEP is a generic term for a medication that you take before the act, yeah. I was mostly refering to Truvada here which is the one that gets most passed around.
[1] https://en.wikipedia.org/wiki/Pre-exposure_prophylaxis