fix syntax

Author: jlin27

fern/docs/pages/0x-swap-api/guides/onchain-swaps-for-exchanges.mdx

@@ -13,7 +13,7 @@ For exchanges and institutions, this creates a clear strategic risk: users who w
 
 ### Proven in Production
 
-Exchanges used 0x to power DEX trading directly inside their main product, giving users access to millions of onchain tokens while preserving a familiar, professional trading experience.
+Exchanges use 0x to power DEX trading directly inside their main product, giving users access to millions of onchain tokens while preserving a familiar, professional trading experience.
 
 [Share the Coinbase case study with your team →](https://0x.org/case-studies/coinbase/exchange/)