Why do you need coingecko specifically?  Do you need data on shitcoins?

If just for Bitcoin data, I would highly recommend hosting your own instance of nostr:npub18d4r6wanxkyrdfjdrjqzj2ukua5cas669ew2g5w7lf4a8te7awzqey6lt3 and using that API

I think they don’t have USD pricing, but there are plenty of other free APIs to get daily price data, and make the conversion from there