My phone says unable to uploaded photos

Troubleshooting:

Turn your iPhone on and unlock it -> enter the passcode.

Go to Settings -> set Auto-Lock to Never.

Connect your device to your computer using an Apple USB cable & try also another USB cable.

Make sure your Mac has the latest version of macOS or the latest version of iTunes.

Check the Wi-Fi connection.

Turn Off Hotspot.

Turn Off or remove VPN if necessary.

See this Apple article: Transfer photos and videos from your iPhone, iPad, or iPod touch

Transfer photos and videos from your iPhone, iPad, or iPod touch to your Mac or PC - Apple Support