In Scratch , preparing an typically refers to the process of exporting your work from the online or offline editor to your computer so it can be shared, archived, or converted into other formats. How to Prepare (Export) an .sb3 File
: Competitions or school assignments often require you to attach the .sb3 file as part of a formal submission process. Scratch Project.sb3
If by "feature" you meant highlighting a project on your profile, you can do this directly on the Scratch Website: Navigate to your page. Hover over the large project box in the center. In Scratch , preparing an typically refers to
: Select "Save to your computer" from the dropdown. Scratch Project.sb3
Are you looking to your project to a specific format or upload it back into the editor?