How do i register apple merchant id without paying 99$ for developer program, only for testing. Thanks.

I'm trying to test my certificate files with curl like this: curl -XPOST -H "Content-type: application/json" -d '{"merchantIdentifier":"merchant..xxxxx","displayName":"TestPay","initiative":"web","initiativeContext":"-***-xxxxxx.xxxxxxxxxx.xx"}' --cert cert.pem:cert.pem 'https://apple-pay-gateway-cert.apple.com/paymentservices/startSession' And I'm receing an error: Failed to import cert file cert.pem, last error is 0x80092002