Turn on Wi-Fi and Bluetooth on both devices

Sign in to the same Apple ID on iPhone and Mac

Enable Handoff on iPhone: Settings > General > AirPlay & Continuity > Handoff

Enable Handoff on Mac: System Settings > General > AirDrop & Handoff > Handoff

Make sure both devices are near each other

Copy text, photos, or other content on the iPhone

On the Mac, place the cursor where you want to paste

Paste with Command + V on the Mac

Keep both devices unlocked while using Universal Clipboard

Update both devices if copy and paste does not work

Restart Wi-Fi, Bluetooth, or both devices if needed