<< Re-sharing the information from the comments here for broader community usage. Thanks >>
@아롬 황 - Post validation with our team, below is the information we could share. Hope this information helps, please feel free to circle back if you have any further queries. Thanks
Azure dashboards is a free offering. Customers can create up to 100 private dashboards and there is no limit on the number of shared dashboards. As for shared dashboards, it is actually an Azure resource, and customer can create as long as they have write permissions to resource group and subscription they are trying to save their resource too.
We will also work to see how this information can be surfaced in our documentation. Thanks again for your query.