The theme will appear in your "Draft themes" list. You can customize it there before publishing it to your live store. ✨ Creating a New Feature
If your premium theme doesn't have the exact feature you need: Go to > Themes > Actions (...) > Edit code . shopify premium themes.zip
Give it a name (e.g., custom-announcement ) and paste your Liquid/CSS code. The theme will appear in your "Draft themes" list