Below are experimented techniques, which may or may not work and may not work in the future. The safest way is to create an account with a phone & SIM in the US.
What has been tried with some success in US targeting comes from using dedicated phones with VPNs (freshly reset with the app store located in the US), AWS EC2 instances in target countries, or residential proxies.
Using a local US SIM card is always optimal.
The process typically takes a handful of videos before you start seeing US locations in your analytics.
Best is to try out various techniques by yourself until you find something that works.
There is a constant stream of people talking about this issue here: https://www.blackhatworld.com/search/20087811/?q=tiktok+target+US&o=relevance
