It won’t allow me to do so. I had Apple TV in the past through a Roku device. I now have an LG smart TV which shows the app on board. I can log into my Apple account on my HP laptop. But I can’t subscribe to Apple TV no matter what I try, through the TV app or via my computer.
Any suggestions?
Had you canceled Apple TV when you moved on from Roku? Maybe you should be clicking on “already have an account” instead of “subscribe”?
Aside: I punted on the apps built into our smart TVs and went back to Roku boxes. Consistent user interface between TVs.
Thanks. I finally got it figured out, but Apple doesn’t make it easy. Yeah, I cancelled it long ago and was just trying to reactivate it. I didn’t realize that it was sending my secret code to the wife’s IMac and not to my phone. Finally (after an hour of farting around with this), I hear “Honey? There’s something weird on my screen!” 
Yeah, I’ve had nothing but headaches trying to subscribe to Apple TV. They’re just the most needlessly complicated service to subscribe to. I had to finally dig up an old iphone I had ten years ago, buy a charger that fit it, charge it, log into it via my Internet connection and have the damn code sent to it. That was the only apple device I ever had. Getting my login info was a pain in the ass too. All for Ted Lasso.
Subscribe, then pirate everything into Plex, but only if you live in an area where this is legal. You’d not be abiding by the license, but you’ll be paying, which is what really morally matters. Again, if you happen to be in a place where this is illegal, don’t listen to my advice.
Happily, I can now watch Apple TV on the TV. However, I can’t watch it on my laptop and have no idea how to make that happen. Shouldn’t my subscription allow me to do both, like every other goddamn subscription service on the planet?
Moderator Note
Since we are owned by a media company, they tend to be a bit sensitive about copyright issues, and saying “only if you live in an area where this is legal” doesn’t get you off the hook.
Do not recommend pirating anything, regardless of where you live.
What happens when you go to tv.apple.com?
I did finally arrive at that sight after my previous post. For a high-tech company, Apple sure makes things clumsy to use.
Preach.
And I appreciate that giving me the warning gets us off the hook. Thank you.
They’re trying to get you to buy an Apple TV device. Works seamlessly on that. If you have other Apple devices it can be worth it, but if you don’t, it’s definitely not.
You go to the Apple TV+ home page, click the “Stream Now” button, then click the “Sign In” button.
That’s seems pretty basic.
The website is unresponsive. No matter what I click on, nothing happens. I had to download an app, which I have to hunt down any time I want to watch something. It works fine on my LG smart TV, now that I have that activated, but it’s very clunky on my laptop.
You have a Smart TV, so you can cast your computer to your TV and watch it on your TV even though it is emanating from your laptop.
I understand that that’s a thing, but have never been able to make it happen. I’m not a techno-dunce, but some things just defeat me. Besides, as mentioned, I was finally able to set the TV up.
See, you’re not a “techo-dunce” at all! 
Not all smart TVs have this capability.
Everyone’s mileage may vary depending on their needs and systems (and budgets). I’ve used Rokus, Amazon Fires and Chromecast devices but I’ve found the Apple TV 4k device to be superior overall for use with my home theater system. It costs a lot more than other streamers but the user interface and build quality are better and worth it IMHO. (I’m a Windows/Android user, I don’t have any other Apple products)
I’ve used Apple TV+ on a Roku, a Fire stick and on Apple TV and it works perfectly fine on all of them. I have not really noticed any major differences.