Checkout integration setting error

hi,
We did all settings of the whmcs integration. Our wordpress and whmcs are in the same server. We add addon domain but in the chechout page, we get an error about enpoint url.
Multisite : http://www.kobimedya.com
Whmcs : http://www.kobimedya.info

Any advice?
Thanks.

Screenshot: https://premium.wpmudev.org/forums/topic/checkout-integration-setting-error#post-650667