This solution works even over a hotspot. Simply enable Portable Hotspot on your mobile device, then connect your laptop to the Hotspot WiFi network.

Tip: If you want to prevent the laptop from using your mobile data, simply switch mobile data off while your hotspot is on. The solution will work even without internet access.

1. Install Cx File Explorer on your Android phone (it's completely free, and has no ads!).
2. If your phone and laptop are not on the same WiFi network, enable Portable Hotspot on your phone and connect your laptop to the hotspot.
3. Open Cx File Explorer (give permission), go to the Network tab and open "Access from PC".
4. Tap on "Start Service". You'll see the full FTP address displayed on your phone.
5. On Windows 10, open File Explorer and enter the full FTP address into the address bar.
6. Press Enter, and you'll see a "device" folder. Open it, and you'll see all the file in your phone. If you have an external SD card, you may see it as another folder besides "device".

The following is optional. If you wish to see this FTP server as a location under "This PC":

1. Open "This PC", right-click a blank space and click on "Add a network location".
2. Click Next, then Choose a custom network location, then Next again.
3. Type in the full FTP address that you see on your phone. Click Next.
4. Leave the option "Log on anonymously" enabled. Click Next.
5. Give your location a name. You can leave it as the IP address or maybe name it after your device.
6. Click Next, then Finish.

The FTP server should open in File Explorer like a normal file system. You can drag and drop files, copy and paste, etc.

This solution works even over a hotspot. Simply enable Portable Hotspot on your mobile device, then connect your laptop to the Hotspot WiFi network.

Tip: If you want to prevent the laptop from using your mobile data, simply switch mobile data off while your hotspot is on. The solution will work even without internet access.

1. Install Cx File Explorer on your Android phone (it's completely free, and has no ads!).
2. If your phone and laptop are not on the same WiFi network, enable Portable Hotspot on your phone and connect your laptop to the hotspot.
3. Open Cx File Explorer (give permission), go to the Network tab and open "Access from PC".
4. Tap on "Start Service". You'll see the full FTP address displayed on your phone.
5. On Windows 10, open File Explorer and enter the full FTP address into the address bar.
6. Press Enter, and you'll see a "device" folder. Open it, and you'll see all the file in your phone. If you have an external SD card, you may see it as another folder besides "device".

The following is optional. If you wish to see this FTP server as a location under "This PC":

1. Open "This PC", right-click a blank space and click on "Add a network location".
2. Click Next, then Choose a custom network location, then Next again.
3. Type in the full FTP address that you see on your phone. Click Next.
4. Leave the option "Log on anonymously" enabled. Click Next.
5. Give your location a name. You can leave it as the IP address or maybe name it after your device.
6. Click Next, then Finish.

The FTP server should open in File Explorer like a normal file system. You can drag and drop files, copy and paste, etc.

For more details and other ways to access the FTP server, see this How-To Geek article.