Redmine REST API Origin not allowed crossdomain Problem

Hi! I worked with a "normal" redmine 1.X Installation and did a ajax API request to get all the projects.

$.ajax({
        type: "GET",
        url : 'http://redmine/projects.json',
        dataType: "json",
        success: function(data){
            console.log(data);
        }
    });

This wored very well.

Now I witched to the bitnami stack version of redmine and get:

Origin "http://otrs" is not allowed by Access-Control-Allow-Origin

...you see: I implemented a connection between OTRS and Redmine to insert Issues..

Is it possible to configure the Apache or the passenger ore somewhat to allow those requests?

Thanks!