Yeah the 915 is in an unlicensed spectrum in us, and 433 has an allocation for unlicensed use in Europe I believe(other countries as well). However, there are many allocations of spectrum in the US where you can transmit data using your amateur radio license. (Which includes the 433 in US. You do need to identify your callsign with the transmissions unfortunately which is the ultimate dox for yourself. (One could also...break the rules)*

*Not suggesting this, just saying. 

FYI I have used metastatic devices in the US of the 433 spectrum (with a license). 

Literally if you study for ten minutes a day on one of the ham radio apps cc: nostr:nprofile1qqszw48usckkhs9hcwt3q3np9k2z2c73s8qc0gu3uxqw66cqlq88ukcpz4mhxue69uhk2er9dchxummnw3ezumrpdejqzynhwden5te0wfjkccte9enrw73wd9hszgmhwden5te0wfjkccte9eek7an9wfjkjemwv4hxw6twv4jhy6twvuhxjmczv5ddh for a few weeks you could take the technician exam, and, they even let you take your license exam remotely in some cases.

I'm telling you just get your technician license and it will be wonderful. You are what ham radio needs!

No joke,  I'll literally buy you a trashy Baofeng if you do it. I'll send you a cashu token worth the cost of one. Hold me to it I dare you.