Since Opera’s browser VPN is built right inside of the browser, you are able to use it immediately without the need for downloading a VPN extension.
To enable VPN in Opera browser:
Go to your Settings (or press Alt+P).
Select Advanced in the left sidebar, and click Features.
Under VPN, toggle on Enable VPN.
After enabling VPN, you’ll see a VPN badge on the left side of your address and search bar, with an on/off toggle for switching on and off the browser’s VPN feature. There, you can optionally change VPN server locations as you wish.
You don’t need to sign up or register to use Opera’s inbuilt VPN feature.