No yet but we could maybe implement that easily. See https://developers.whmcs.com/api-reference/
There is surely a bug so. Please try to edit the /var/www/imscp/gui/plugins/WHMCS/frontend/whmcs.php file and at line 394 change:
by
once done, restart the imscp_panel service and retry.
Ok, that was the solution, thank you!
And feature developements too!