To resolve the issue of not being able to add widgets from the Couple Joy app to your lock screen, follow these steps:

1. Ensure App Compatibility and Update:
- Confirm that you are using the latest version of the Couple Joy app. Go to the App Store, search for the app, and if an update is available, download it.

2. Add Widgets Properly:
- Long press on an empty area of your lock screen.
- Tap on "Add Widgets" that appears on the menu.
- Choose the Couple Joy app from the widget list and select the widget you want to add, such as the distance widget or the days together widget - learn more.

3. Check App Permissions:
- Go to Settings > Privacy > Permissions and ensure that Couple Joy has the necessary permissions enabled.

4. Restart Your Device:
- Sometimes, simply restarting your iPhone can resolve any temporary glitches preventing widgets from appearing.

5. Offload and Reinstall the App:
- If the app still doesn’t appear as an option, try offloading it. Go to Settings > General > iPhone Storage, find the Couple Joy app, and select "Offload App." After that, reinstall it - learn more.

6. Check System Software:
- Make sure your device is running the latest version of iOS compatible with widget functionality. Update your iOS if there’s a new version available.

7. Try Adding Other Widgets:
- To ensure the issue is specific to Couple Joy, try adding other app widgets. If other widgets work, the problem may be with the Couple Joy app itself.

If you follow these steps and the issue persists, consider reaching out to Couple Joy's support for further assistance. They may have more insights specific to the app's compatibility or any ongoing issues with iOS widgets - learn more.