Mutation.customizeTheme
Open a theme for editing in the Customizer. If the theme is currently 'main', returns (or creates) a draft clone whose parent_theme_id points back at the main; if a draft already exists for this main it is returned unchanged so the merchant continues their in-progress edits.
ReturnsStoreTheme!
Signature
Open a theme for editing in the Customizer. If the theme is currently 'main', returns (or creates) a draft clone whose parent_theme_id points back at the main; if a draft already exists for this main it is returned unchanged so the merchant continues their in-progress edits.
theme_idID!