VPN and TOR are both allowed, there is nothing that will block anything that helps you stay anonymous, neither is there any risk of getting banned while using the service anonymously, as long as you are respecting the terms of service.
However, when using VPN or TOR from a different country, make sure that the country code in your account is your real country. This is for tax reasons, as payment providers can trigger a temporary account suspension if there is a mismatch in countries.
You can check this in your profile settings: https://dash.99stack.com/user/profile.
If the country code there is incorrect, contact support as soon as possible to correct that information.