To perform meta-transactions, a user needs to sign a message. After a user signs it, DApp sends the message to a relayer who sends that message into an actual transaction to a public node so the transaction can be mined.
Biconomy is the scalable relayer infrastructure network and transaction management platform enabling DApps to reduce the friction between DApps and end-users.
Mexa integration is a two step process
Register your DApp on Mexa Dashboard, a dashboard for developers, and copy API Key generated for your DApp.
Integrate Mexa SDK in your DApp code using API Key you got from dashboard.
Lets see how a DApp is registered on dashboard and SDK is integrated in next section.