Thank you for always using the Easy Custom Options.
Now that the specifications of Shopify have changed, the use of a new mechanism called ScriptTag will be discontinued, and the use itself is also scheduled to be discontinued next year.
In addition, we have also provided this support for the Easy Customization option.
Since it supports AppEmbed, if the guide is displayed on the top page, could you follow that guide to open the settings?
If it doesn't appear, you can do so from the Shopify store management screen.
Sales channel -> Online store -> Edit the theme (current main theme)-> Embed app icon (top left of screen)-> Enable custom options
By implementing this setting, it is possible to have the settings reflected.
Thank you in advance for your cooperation.