Mutation.installPresetTheme
Install a template/preset design into a store as an unpublished draft (clone of the chosen template). Publish/activate it to switch the storefront.
ReturnsStoreTheme!
Signature
Install a template/preset design into a store as an unpublished draft (clone of the chosen template). Publish/activate it to switch the storefront.
template_idID!store_idID!