CoinGecko maintains an exchanges listing at https://www.coingecko.com/en/exchanges.

To have your exchange listed, do fill up this form: https://forms.gle/88Yz2Byi6EiheYA78

Listing is free but CoinGecko will verify the trading volume and credibility of the exchange before adding it. To check on listing status, do kindly email hello@coingecko.com