If Maverick is not whitelabelled, you can connect it using an authorization link.
If this is the case, please send this authorization link to your merchant: https://dashboard.maverickpayments.com/appConnect/default/auth?id=8&authToken=52351adda970c2bdc7712cfa914ade5fdc18e4df1a4e6cde610a15250662135d
If you do whitelabel Maverick, you will instead use a connect page for the integration.
The merchant (or you) will need to go "Security" then copy their connect ID. Then, they will paste this on the connect page and accept the permission request.