Update - it worked! Worth noting is this was our TV - can't confirm it would work for other TV's.
https://www.bestbuy.com/site/sharp-75-class-led-2160p-smart-4k-uhd-tv-with-hdr/6296542.p?skuId=6296542
We just got an e-mail from HiSense - testing this out
Thank you for contacting Hisense. You will find a link to the FW Update Download below. Please follow the below instructions to update your TV�s Firmware.
FW Upgrade Download...
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