You are lucky but those only work in China because it uses a e-sim.
I agree that the tech has regional limitations, yet in the US Occusync 4+ is fully permitted by the FCC. - yet they are unlikely to permit the combined 4G-Occusync 4+ "enhanced transmissions" , but e-sim, tech works everywhere -
DJI says the following:
The DJI Cellular Dongle (4G) supports enhanced transmission in a wide range of European countries and also in Australia and New Zealand. Specifically, it works in Austria, Belgium, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Monaco, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland, and the United Kingdom. While it's also functional in Australia and New Zealand, the list of officially supported countries on DJI's website may not include these regions.