If they sell a VPN service, you can safely disregard anything they tell you about Tor.
The warning in your screenshot in particular looks like pure bullshit.
Warning! You aren’t using our service! Please stop using a tried and true method and instead pay us money!
Can you please provide some context or a specific topic for discussion? It is difficult to reply to a sentence without any reference to what it pertains to.
They are just letting you know that it is possible to know that you are using some method to remain anonymous. If you enter the website with nothing, they will inform you that it is not possible to identify whether you are using some method to remain anonymous.
whoer is more for how realistic your disguise is. probably something to do with your tor ip and dns are a different location combined with an incorrect time zone. tor is for anonymity, that doesnt mean its gonna look realistic.
When you open whoer.net on tor browser, it shows that your connection is not secure.