Source-only tasks can help you improve the quality of your texts before you submit them for translation. You can also use task types to register the activity of your content creators on the platform. This means that tasks are defined as monolingual so you can focus on one of the languages of your project.
They will carry the language you need to work on as "source" and (Any language) as a target.
The configuration will look as follows.
You can also configure them having the (Any language) definition for target, as done for in-house suppliers.
Make sure the user profiles and price lists have been set up to perform these tasks.