0x's Liquidity Integrations team is responsible for sourcing and adding new liquidity providers to the 0x API, which Matcha relies upon. If you would like to request the 0x Liquidity Integrations team review your DEX, AMM or liquidity pools, there is a form you can fill out to indicate your interest in becoming a 0x API liquidity source:
For more information regarding our Liquidity Sources, please visit the 0x Documentation hub.