No, there is no subscription to use a Roku device (player or Roku TV). You set up a free user account, then when you first set up your Roku you link it to that account. You can then install apps (called channels on Roku) and use them. Since you have a Hulu subscription, you install the Hulu channel and log into it with your Hulu credentials.
Again, there is no fee to use a Roku device, other than the original cost to buy it. If someone is telling you that you need to pay for a "premium" user account, or to link the device to your Roku user account, they are trying to scam you into paying something that isn't required. There is no such thing as any Roku user account that requires a payment or subscription.
Are there channels that you can install on a Roku that require a subscription? Certainly, such as Netflix, Prime Video, Hulu, etc. But there is a lot of content available absolutely free, such as YouTube and many ad-supported streaming sites.
Dan
Roku Community Streaming Expert
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