I haven't looked into this in a heap of detail but I think you could sign up for a free t-mobile trial according to this reddit post?
https://www.reddit.com/r/NoContract/comments/tuzez7/looking_…
"So you have an iPhone, try using T-Mobile's Test Drive eSIM app. 30GBs of data, unlimited calls and text. Only requirement is iPhone and eSIM. No Credit card or anything.
Trial is once every 6 months.
Edit Link; https://apps.apple.com/us/app/t-mobile-network-test-drive/id…
What a hack! I wonder if anyone has a good hack to get an esim (preferably) for the Usa? Cheapest I found is Airalo which offers 10gb for $19 us with a code (1 month validity).