I paid for a key of Office 2019 Professional Plus, so a little more than your typical key. I immediately had issues and used every solution offered. Their response time has been awful. I activated the product on Saturday and didn't receive a response until Friday. Almost five business days and then just before another weekend to guarantee more waiting! Next reply also took a few days.
The key did not work through Microsoft's Office activation website and initially error-ed out when trying to send the key through the Office software. This provided a lot of doubt as to the legitimacy of the key.
Another thing they offered was to use PowerISO, which was completely irrelevant when Windows Explorer opens the. Img file provided and mounts it as a disk just fine. So of course I wasted a bit of time verifying the trustworthiness of that software (and making sure I didn't have to pay) and used it's trial to get the same effect.
I did finally get the product working with a Registry Edit following this support post from Microsoft: https://support.microsoft.com/en-us/office/office-error-code-0x80070005-when-activating-office-7aa7600f-df57-4aef-81d2-25509c66f865
They provided this solution, but the problem here is that Microsoft's instructions are incomplete. "NETWORK SERVICE" does not appear by default. Therefore you have to press "Add" > "Select a principal" then type "NETWORK SERVICE" exactly (without quotes, but with a space) and click "check names" to be sure it works. Give it "Full control". Press OK. Check the "Replace all child object..." while "NETWORK SERVICE" is selected. Press OK. An error will come up, but it should have worked. After that point "Unlicensed Product" no longer showed up. I'm not sure why this solution was required.
I still cannot recommend the site due to slow response and general shadiness but it does not appear to be a complete scam.