as stated browsers do not support opening a file explorer. there are some common solutions:
- use a file server that supports browsers. move the to a sharepoint library, or to office 365 one drive. in this case you link as required by the service.
- use IIS file browser support. This works best with local files. if you use a file share, then the access is based on the IIS account, not the user. You appear to need permission support, so the file share server would need to host the IIS site
- Create a web site that that exposes the file share as links. you may need folder support and both upoad and download. You will need to write your own security. Many of the 3rd party control companies make a file manager compoent you can start with. https://www.telerik.com/aspnet-core-ui/file-manager
- Create a tray application that the client installs. this application would support web service call on a custom port. using javascript the tray application is called, and it open the explorer windows. this is the only option that does exactly what you want.
- Create a tray application that the client installs. this application would support web service call on a custom port. using javascript the tray application is called, and it open the explorer windows. this is the only option that does exactly what you want.