exporting and importing sharepoint sites

This is one of the differentiators between premium and non-premium features in Microsoft 365. Solutions are the way that Power Platform developers package security, flows, apps, and forms to move between environments, but they typically use a premium datasource such as Dataverse, not SharePoint.

SharePoint does not have environments - you can export and import various things with PowerShell or third-party migration tools, but there is not an easy way to move it between environments in a package like you do with solutions and Dataverse. You can assign SharePoint site URLs as an environment variable to make it easier to move, but it doesn't go into the "package" itself if that makes sense. This is part of why the upsell to premium exists, they're not going to make it easy for you to replicate the features of the premium product. 🙂