Use the Theme Updater to obtain the latest version of your theme in its default state. The theme will be added to your Online Store as an unpublished theme.
Paid plans for the app are not needed to use this feature. However, this process requires that the app is installed and the theme has been registered. If necessary, complete these tasks first to add a new copy of your theme.
Add a new copy of your theme
Open the Theme Updater through your Apps admin to access the main page. Locate the block for your registered theme. Any copy or version of the theme will work, so long as it has been successfully registered.
Select Actions, then Install default theme.
A pop-up will open to confirm the process.
Select Install to complete the task.
The Online Store can accommodate up to 20 themes, including the published theme. You may need to delete an unused theme to make room.