I have a wordpress site and have intergrated pesapal using this plugin below, now everything seems to be set up correctly but when I click on the payment button, I get the "Problem: signature_invalid | Advice: > |" error, not sure what the problem is, the plugin creator states that its a credentials issue with pesapal but I have checked and rechecked the credentials and they are installed the way they were sent to me. Some help to get this going would be appreciated. Thanks
Regards
Ro
wordpress.org/plugins/pesapal-pay/ 
