Hi there! I see you're having trouble proceeding to checkout in the Rakuten app on your iPhone. I’d love to help get this sorted for you.

To start, could you tell me if you see any specific error messages when you try to check out? Also, have you already tried any steps like re-entering your billing info or restarting the app?

In the meantime, here’s a straightforward troubleshooting path we can follow:

1. Check your billing and shipping info: Sometimes if a field is incomplete or incorrect, checkout won’t proceed. Try re-entering your payment details carefully.

2. Log out and log back in: Signing out of your Rakuten account and signing back in can refresh your session and clear minor glitches.

3. Clear the app cache: While iOS doesn’t have a simple cache-clear option like some Android devices, you can try force closing the app fully and reopening it.

4. Update the app: Make sure your Rakuten app is updated to the latest version from the App Store, as bugs get fixed regularly.

5. Try switching networks: Sometimes checkout issues can stem from network problems. Try switching from Wi-Fi to cellular data or vice versa.

6. Check for any blocked pop-ups or settings: Since you're using iOS 18.7.1, ensure any content blockers or privacy settings aren’t interfering with the app.

If none of these work, I can help guide you through a few more advanced steps, or if needed, escalate the issue for deeper investigation.

Could you please let me know what you’ve already tried or any error details you’re seeing? That’ll help me pinpoint the best next steps for you.