we have a problem connecting the newsletter2go extension for Magento 1 properly to our shop.
connecting to the n2go service from within the magento admin backend worked. But when goin to the newsletter2go backend to check the integration, we cannot complete the setup (Button "Einrichtung abschließen"). Our magento api responds with 403 error, see screenshot. I know that this works with magento´s built-in API2 mechanism. Any ideas what to do?