Many payment processors offer an "Authorize.net Emulator". This allows you to setup a 3rd party Payment Processor who is not specified as an integration partner by setting them up under "Authorize.net Payment Gateway".What are the options for using a payment processor who is not specifically supported?
Some examples are: 1st Pay and RedFin
The 3rd party Payment Processor will provide you with the credentials that you need, and you can enter them under "Authorize.net Payment Gateway". The most important part is they will also give you an "Alternate Endpoint" or "API Endpoint". It will look like a website address. Be sure to enter this in as well so that the payment information is sent to your 3rd party Payment Processor.
Here is a video that will show you how to setup your payment methods in AllProWebTools: