Import photos via Wi-Fi

Your devices should be on the same Wi-Fi network.

Run HashPhotos Transfer on your Mac or PC
(HashPhotos Transfer can be downloaded on https://www.hashphotos.app for macOS or Windows)
Tap three dots button on the bottom left of the thumbnails screen.
Tap Add button.
Tap Import from Mac/PC.
Select a device to connect on the device picker.
If it's the first time, click Allow button in HashPhotos Transfer on your Mac/PC.
Drag and drop your photo files into HashPhotos Transfer on your Mac/PC.

If the device is not detected, try turning off and on the Wi-Fi of all devices.
If still doesn't work, try restarting your router too.
Also, check Firewall settings on your Mac/PC.
HashPhotos Transfer and Bonjour service should be allowed in your firewall settings.