No.
You do not have to pay yearly for Roku.
The Roku Device requires no monthly subscription or activation fees and all you have to do is buy the Roku device and have an internet connection.
You can watch free channels on the Roku device such as Youtube, PBS Kids etc and even the Roku Channel for free.
There are some channels that require a subscription but you don't have to subscribe to them if you don't want too.
If someone calls you saying they are from Roku support and that you need to pay a fee then they are scammers and you should not pay them.
Roku Support is free and not paid.