In order to start testing, please contact us to obtain a reseller id. Once you have the reseller id you would first call the pairTerminal() method of the api which will return an API Key/Pwd and terminalID which you would store on your end. You would then use those credentials with the runTransaction method to run a sale. Please be sure to read the area in red on the pairing page as it describes the importance of the referenceID when calling the pairTerminal method.
All commands require a key, pwd and terminalID parameter which is obtained from the pairTerminal method.