Tap the account switcher in the top left corner and you should see the option.
See my comment for a screenshot. I don’t know why I can’t seem to post a screenshot in the body of post. Every time I try it gets removed.
You need to update your app to the new beta. Ad-free only option is separate, does not cost $100+.
I downloaded the app about 20 minutes ago, and Lifetime Ultra is $169.99 for me in Australia. Am I doing something wrong?
Remove ads is its own menu item, clicking it directly shows you the payment prompt.