Verify a VPN or Proxy With an IP Check
A VPN should change the public IP and, usually, the country. InstantIPCheck also shows DNS and WebRTC so you can catch leaks when the IP changed but other signals did not.
What “working” looks like
With the VPN connected, the homepage IP and city should match the provider’s advertised region, not your physical network. ISP/ASN should belong to the VPN, not your home broadband.
Then check DNS: resolvers should not still be your ISP. Check WebRTC: local or ISP addresses appearing there are a common leak even when HTTP shows the VPN IP.
What a pass does not prove
A clean IP check does not prove the VPN vendor is trustworthy, that traffic is uncorrelated, or that the browser fingerprint is generic. It only shows what this page can observe right now.