Not a direct source but https://africacheck.org/fact-checks/spotchecks/yes-nigerian-... pops up as a fact check after the same claim was made by Candace Owens. This link (from 2018) refers to several reputable sources of the time. I would guess that there are updated data from the US Census Bureau et al if you want to double check, but from all sources linked it seems Nigeria is and has been on an upward swing as far as exporting educated, successful people to the U.S. (and perhaps retrieving them to prevent brain drain, but I cannot be sure).

FWIW and from anecdotal accounts of acquaintances of mine (not a lot but in the double digits), this comes down to a cultural focus on education and family structure from a young age. Compare to the culture and family values promulgated elsewhere.