Here are a few. Don't know how long will it to get to you.
https://us.amazfit.com/products/charger-for-amazfit-band-7
https://www.amazon.com/Lettou-Charger-Cable-Replacement-Amazfit/dp/B0BDTWZS74/
Have you tried ebay?
https://www.ebay.com/itm/304722091297?hash=item46f2da1d21:g:wSUAAOSwVLtjh1sH
https://www.ebay.com/itm/175635501097?hash=item28e4b11029:g:NQ8AAOSw\~CJkAD9i