Many states in the USA are now allowing REMOTE Notarization. A Remote Notary in the USA can notarize for anyone in the USA and Outside the USA. The Process is completely virtual, and very easy. You have to do it all through secured platforms created for this service. Do an online search for RON services.
You are correct with respect to some states, but not all.
The Covid-19 pandemic has forced many states to recently adopt emergency procedures for remote notarization.
However, and since it is state specific, you need to check each states regulations. By way of example, Massachusetts will only allow a remote notarization of a document if BOTH parties are located somewhere within the state.
It is a case by case, state by state basis.
If your state does not allow it, then short of flying back to the US, the Embassy/Consulate is your other choice.
Respectfully,
Playacaribe2