Appmixer comes with set of prepared components (applications). Some of them use OAuth 1 (Twitter) authentication mechanism and some of them (Slack, Google) use OAuth 2 authentication mechanism.
If you try to use Slack component right after fresh Appmixer installation you will get an error
Missing client ID.
In case of OAuth 1 application the error will be
Missing consumer key. As described in here the OAuth applications need these secrets. The reason we do not provide these secrets with Appmixer is simple. Part of the OAuth application registered in the third party service is the redirect URL which points to your server URL where the Appmixer backend API is running.
Therefore you need to create these OAuth application on your own. At the end of the process you will always get client ID and client Secret (OAuth 2). Appmixer expects these variables to be part of ENV. Here is the list of all ENV variables that you can set for the pre-packed applications if you want to start using them.