Failed to refresh example/availability

cURL error 60: SSL certificate OpenSSL verify result: unable to get local issuer certificate (20) (see https://curl.haxx.se/libcurl/c/libcurl-errors.html) for https://example.com/availability.xml

Duration: 0.05s

Feeds

Click Refresh to manually trigger a feed update

Supplier Feed Interval Last Updated Size Status Actions
example products 6 hours Never Not generated
availability 30 min Never Not generated