Fentanyl was created in the US in the 1960, so isn't it more likely we create most of it?

Nearly all is manufactured in Mexico. Source, DEA:

Nearly all the methamphetamines sold in the United States today is manufactured in Mexico, and it is purer and more potent than in years past. The shift to Mexican-manufactured methamphetamine is evidenced by the dramatic decline in domestic clandestine lab seizures. In 2023, DEA’s El Paso Intelligence Center (EPIC) documented 60 domestic methamphetamine clandestine lab seizures, which is a stark comparison to 2004 when 23,700 clandestine methamphetamine labs were seized in the United States.

https://www.dea.gov/press-releases/2024/05/09/dea-releases-2024-national-drug-threat-assessment

“Fentanyl was created in the US in the 1960, so isn’t it more likely we create most of it?”
– non sequitur logic

No, cartels are everywhere and last fall this was not big news for some reason.
https://www.nytimes.com/2025/01/30/world/canada/canada-fentanyl-trump.html#:~:text=In%20November%2C%20officers%20in%20British,showed%20links%20to%20Mexican%20cartels.