webhook fails to create bug report

Hi, I found an issue regarding express checkout setup.

Environment:

• WordPress 6.9.1
• WooCommerce 10.5.3
• Klarna Payments for WooCommerce 4.6.1
• PHP 8.2.30
• Live mode

Issue:
When I go to WooCommerce > Settings > Payments > Klarna Payments > Express Checkout and click Create Webhook, the webhook is not created.

What happens:

• The admin request reaches WordPress correctly.
• The nonce is valid.
• The plugin handler runs.
• It fails at the signing key step with Could not create signing key.
• No kec_signing_key or kec_webhook option is saved.

Root cause:
In the KEC notification request base URL, live mode generates an invalid URL with a double dot:

https://api-global..klarna.com/v2/notification/signing-keys

This appears to come from:

dependencies/krokedil/klarna-express-checkout/src/Requests/Base.php

Current logic:

$environment = $testmode ? 'test' : ''; return "https://api-global.{$environment}.klarna.com/";

In live mode, this becomes:

https://api-global..klarna.com/

Expected live URL:
https://api-global.klarna.com/

Suggested fix:
Either:

return $testmode ? 'https://api-global.test.klarna.com/' : 'https://api-global.klarna.com/';

or:

$environment = $testmode ? '.test' : ''; return "https://api-global{$environment}.klarna.com/";

Temporary workaround:
I added a WordPress filter that rewrites only the malformed URL from:

https://api-global..klarna.com/

to:

https://api-global.klarna.com/

After that, Create Webhook worked correctly.