If I pay for Netflix through my iTunes account?

am I only allowed to watch it on Apple devices?

So if I buy Netflix through my iPhone and have it charge through my iTunes account, am I only allowed to watch it on Apple devices such as AppleTV, iPad, and iPhone or am I able to watch it on other devices such as XBOX, Roku, Amazon TV, smart TVs, etc?
Added (1). So if I created the account through an Apple device, would I create the username and password for Netflix? If not, then how would I log in on other devices because they wouldn't as for my iTunes username and password?

Read more: If I pay for Netflix through my iTunes account?