https://www.esri.com/arcgis-blog/products/arcgis-storymaps/constituent-engagement/getting-started-with-templates-in-arcgis-storymaps

ArcGIS Hub site templates enable organizations to quickly deploy pre-configured website layouts, automatically generating associated items like maps and apps to expedite community engagement site creation. The workflow involves activating a template from the gallery, which allows users to immediately edit, brand, and populate the site with custom spatial data. For more details, visit Esri Documentation. Edit a site—ArcGIS Hub – Esri Documentation