Hi kemi49,
Thanks for using Apple Support Communities. We understand that you don't have access to the iTunes Extras. Check out the link below that has some troubleshooting steps to help with not being able to view the Extras on the movie you purchased.
If you can't view your iTunes Extras
- Make sure that you have a strong Internet connection
Connect your device to a Wi-Fi network and try again. If you're using an iPhone or iPad with a cellular connection, make sure that cellular data is turned on for the Apple TV app in Settings.
2.Check if the movie has iTunes Extras
On your iPhone, iPad, iPod touch, Mac, or Apple TV, open the Apple TV app, then go to the Library tab. On a PC, open iTunes for Windows, select Movies from the menu in the upper-left corner, then select the Library tab.
Select a movie to see its description page. If a movie has iTunes Extras, you'll see an iTunes Extras badge.
If you didn't buy the high definition (HD) version of the movie, or if you rented the movie, then the movie won't have iTunes Extras.
"iTunes Extras aren't available in the Apple TV app on smart TVs and streaming devices."
3.Update your software
Make sure that your iPhone or iPod touch is updated to the latest version of iOS, iPad is updated to the latest version iPadOS, Mac is updated to the latest version macOS, and Apple TV is updated to the latest version tvOS. On a PC, make sure that you're using the latest version of iTunes for Windows.
4.Get more help
If you still can't view your iTunes Extras, you can report a problem with your purchase.
Let us know how this goes.
Regards.