Cannot select syncing location

[jimmyfarmer123]

I'm trying to setup freefilesync on my sister's laptop.
She has an external hard drive hooked up to her asus router but when I select the folder on the external hard drive to sync to I get the following error.

The selected folder "this pc\rt-ac86u-4870\browse folders\josie_s_backup\documents" cannot be used with freefilesync.
Please select a folder on a local file system, network or an mtp device

I have the identical setup at my home and it works fine but I use Linux and she uses windows 10.

What is strange to me is the "browse folders" folder was just there, I never created it after I formatted the hard drive. There is also a "music" and "pictures" folder that appear on the Ext hd that I never created either. Not sure if asus does this automatically when on a windows computer or what may have caused the automatic creation of these folders?
The folder I made was named "Josie's backup" and I created it through the router's web interface. I'm wondering if maybe freefilesync doesn't like the ' or the space in the folder name? I unfortunately didn't have a lot of time to troubleshoot when I was at her place. I can't usually go over until after my kids are in bed and then she works early in the morning so I have a limited window to work with to try to get things setup for her. I'm going to go over tonight again but if anyone has any ideas or suggestions that might help that would be greatly appreciated

[Zenju]

The selected folder "this pc\rt-ac86u-4870\browse folders\josie_s_backup\documents" cannot be used with freefilesync.

That's a strange path. Are other programs able to work with this? Maybe we're lucky and it's only a formatting issue, e.g. could be an alias for a network path like "\\rt-ac86u-4870\browse folders\josie_s_backup\documents"

[jimmyfarmer123]

Thanks for responding, I figured it out last night. I needed to install an additional windows networking feature. I can't remember exactly what it was called but everything is working now.

Thanks again