Hello Maximilian Becker,
Welcome to Microsoft Q&A! Thanks for posting the question.
To publish a model, it must first be trained. Training is a prerequisite step, as it prepares the model with the data and configurations needed for deployment. Without a trained model, publishing is not possible. For more information, kindly refer this document Publish a custom model.
If the subscription is free, Create a Paid Subscription by upgrading the existing Translator resource to a paid tier. Choose an appropriate plan based on your deployment and usage requirements. This can be done directly in the Azure Portal under the resource’s Pricing Tier settings.
By verifying your subscription, upgrading to a paid plan, and reconnecting your workspace, you can resolve the issue and publish your model successfully.
I hope you understand, do let us know if you any further queries.
Thank you!