Go to Configuration > click Payment Gateways > Click New
Give this payment gateway a Name. It is recommended that the name has a reference to Converge (or Elavon) for easy selection.
In the Payment Gateway selector, select Converge.
In Payment Gateway Settings, select either Development or Production in Account Mode depending on the organization's Converge/Elavon credentials.
Depending on the account mode selection, provide the organization's development or production
Merchant ID, the User ID, and the PIN.
Finish configuring the fields in Billing Settings as preferred.