Thank you for provided information. By default, you cannot enable public share on the router, as it is considered not secure as you will be sharing your shared USB flash drive to the "world". But if you are ok with this, there is possibility to enable public share.
1. Connect USB flash drive to routers USB type A port.
2. Navigate to USB Tools section and enable network share (aka Samba). More information: https://wiki.teltonika-networks.com/view/RUT955_USB_Tools#Network_Shares make sure to configure Shared Directories
3. Connect to the RUT955 via SSH and use the following commands:
- vi /etc/config/samba
Now by using arrows on your keyboard navigate to samba configuration, then press letter "i" on the keyboard to edit and make sure the configuration looks something like this:
option name 'Router_share'
option workgroup 'WORKGROUP'
option description 'Router share'
option homes '1'
option enabled '1'
option interface '<wan interface name>'
Where option interface make sure to use correct WAN interface. WAN interface name can be found by using command ifconfig.
Once finished editing, press "Esc" on keyboard and type :wq!
4. Restart samba service by using command /etc/init.d/samba restart
5. Connect to RUT955 WebUI, navigate to firewall settings and open new TCP port 445.
If everything done correctly, you should be able to access your shared USB folder over th internet.