We setup invoiceplane and are trying to setup a sandbox account to test with and it’s constantly failing with
Payment failed. Please try again.
Security header is not valid
I’ve seen other posts saying we need curl so we’ve installed curl and php-curl but it still errors out. I’ve tested the username/password/signature using the paypal method to test with curl and it seems to be fine. Here’s the curl command I used to test in shell.
Any suggestions on why this might not be working? I’m wondering if some other dependency is not installed but the system is not complaining about it just like php-curl or php-mbstring.
I should have mentioned this is the latest 1.5.6 IP