Before using the remote FTP access function, it is necessary to set up port forwarding at the router, the following is a method for port forwarding on the router,
1. By entering the password for the administrator account login to the router control page;
2. Find a port forwarding module, for example, NAT,

3. Click "NAT" to edit the TCP protocol, NAS IP addresses, passive FTP port and port and save the Settings (for example: 192.168.1.2 instead is the IP address of the your TNAS, 21 is FTP port, 55536-56559 is a passive ports),

4. You can find the router in the login page of Internet static IP address (public IP), then you can enter in through the Windows File Explorer: ftp://171.250.52.150 to remote access via FTP service TNAS,

Suggest you to download and install on PC FTP client (such as FileZilla, WinSCP, etc.) to access the TNAS,