Connect your iPhone to your Mac with a USB cable
Unlock your iPhone and tap Trust This Computer if prompted
Open the Photos app on your Mac
Select your iPhone under Devices in the Photos sidebar
Choose the photos you want to import
Click Import Selected or Import All New Photos
Wait for the transfer to finish
Open Finder on your Mac
Select your iPhone in the Finder sidebar
Click Photos in the top menu if syncing is available
Check Sync photos to your device from
Choose Photos, Pictures, or a folder on your Mac
Select All photos and albums or Selected albums
Click Apply or Sync
Turn on iCloud Photos on your iPhone
Go to Settings on your iPhone
Tap your name
Tap iCloud
Tap Photos
Turn on Sync this iPhone
Turn on iCloud Photos on your Mac
Open the Photos app on your Mac
Go to Photos > Settings
Click iCloud
Turn on iCloud Photos
Make sure both devices are signed in with the same Apple ID
Connect both devices to Wi-Fi and power if using iCloud sync
Check the Photos app on your Mac after syncing completes