Please help :
We failed and could not save the Paypal Signature API data and always appear Disable, could not save to enable.
Our website is only given instructions set:
Username API:
Password API:
Signature API:
display an error message if the save will appear in the billing settings paypal adminpanel our website:
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" Gateway login failed. Please double check your connection information. The gateway has been disabled. The message was: [0] Invalid HTTP response version: 2 "
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We ask for your help and guidance
Thank you
