Hi Muhammad,
You can just click "Allow Access", this option will require administrator permissions. If the problem occurs every time you try to open the browser, you can disable the firewall for it.
- Open settings by pressing the Windows key on your keyboard and selecting the gear icon.
- Select Network and internet, then go to WiFi.
- On the right of the application, select "Windows Firewall"
- Then select "Allow an app through the firewall", and find the Opera Browser.
After applying these settings, the problem should no longer persist. I hope this helped,
Freddie.