National flags are often protected from unauthorized commercial use. Many countries have specific laws regulating how their flag or emblem is used. Using flags in trademarks or on products is strictly restricted in many jurisdictions, including the US, EU, and India.
Besides, Stock already has all the Regional Flags they need.
https://stock.adobe.com/search?k=national+flag 5.7 million results
https://stock.adobe.com/search?k=country+flag 6.1 million results
https://stock.adobe.com/search?k=state+flag 6.7 million results
See Illustrative Editorial Content below:
https://helpx.adobe.com/stock/contributor/help/illustrative-editorial-content.html
Even if yours was accepted as Illustrative Editorial content, there’s too much competing content for yours to be seen much less purchased.
Hope that helps.