Hey Ulli! I'm helping, see?!?!?!
@Pharon, have you set up a Channel yet? There's stacks of documentation on setting up a channel, or just hit the Channel tab/link in AutoTweet, click NEW and fill in the first two fields, then click that big "Authorise Application And Grant Permissions" button, follow the prompts, copy and paste the codes and you're off.
Also note that with the K2 extension and the latest version of Autotweet it takes a little time for the Twet to end up in the Job Queue, bit it will.
And about the force autotweet to add manually and send later, make sure that on the Channel you've just created, the option to Autopublish is off AND the K2 Plugin Autopublish is off. That way you can head to the job queue and post tweets when you're ready, and they don't auto send.
Does that help?