Amazon, you can order cable for GTR 3 and T rex 2
https://www.amazon.com/Kissmart-Charger-Amazfit-Magnetic-Charging/dp/B09VBHWF88/ref=sr\_1\_1\_sspa?crid=LGJQNU2LUPDE&keywords=charging+cable+gtr+3&qid=1663232238&sprefix=charging+cable+gtr+3%2Caps%2C161&sr=8-1-spons&psc=1