the module does not take in nsg id as an input and thats necessary to allow network traffic across subnets where instances mounting file storage are running.
the resource file_storage_mount_target has an optional parameter nsg_id which can be used to implement this.
I believe this can be done by adding the nsg_id parameter in the file main.tf below line 96 (highlighted)
could you take a look and provide a suggestion for this use case.