CPO here: if you want to use any service in a u safe third part country (US) you have to follow this recommendations [0]. They are up for consultation untill end of December.

If you want to play it safe: Only transfer personal information out of the EU into a unsafe country if it is fully encrypted and only you Organisation holds the keys. More on that in the link but thats the gist of it.

[0]https://edpb.europa.eu/our-work-tools/public-consultations-a...