I'm very lost with the gateway. It seems that Authorize.net is highly supported with Craft Commerce but the gateway isn't working. I had the dummy gateway working perfectly fine. I'd so that when I'd go through the whole processes and the order would show up. I put in authorize.net AIM as a new gateway and now when I get to the payment it does nothing at all. I put in this code:
{% if craft.config.devMode and (craft.session.hasFlash('notice') or craft.session.hasFlash('error')) %}
{% set noticeFlash = craft.session.getFlash('notice')|join('|') %}
{% set errorFlash = craft.session.getFlash('error')|join('|') %}
Notice: [{{ noticeFlash }}]
Error: [{{ errorFlash }}]
{% endif %}
and I get back
Error: [Payment method does not exist or is not allowed.]
I've put in the API user and key and the link at the bottom. Am I supposed to set the gateway as default somewhere?