Greasy Fork

The "Download subs for this episode" button does not appear on https://www.amazon.co.jp/ after following the steps below. Is there any way to make it appear?
I have installed 1.9.15 on Edge with developer mode turned on.

1. Clear the browser cache
2. Restart the browser.
3. Open https://www.amazon.co.jp/gp/video/detail/B01ISA7614/
   ->I have confirmed that the script is running at this point.
4. Log in
5. Play episode 1.
6. Close the player screen by pressing X button.
7. The"Download subs for this episode" button is not displayed on the episode screen.

Thank you.

Additional information.

• At https://www.amazon.co.jp/gp/video/detail/B01ISA7614/ it does not show up with or without login.

• At https://www.amazon.co.jp/gp/video/detail/B07FMKBFC7 the situation is as follows

  • When Not logged in
    The "Download subs for this episode" button is displayed on the episode screen.
    But when I press it, it pops up "No subs found, make sure you're logged in and you have access to watch this video!".
  • When logged in
    The "Download subs for this episode" button is not displayed on the episode screen.
    Debugging shows that the async function init(url) is not called.