Oh no, it sounds like you've run into an issue with the Sam's Club 'Scan and Go' feature not launching. Let's see if we can sort this out for you.

First, just a quick confirmation—have you already tried restarting your iPhone? This simple step can clear up minor glitches that might prevent apps from functioning properly.

If restarting didn’t help, here are a few more steps you can try:

1. Update the App: Ensure that the Sam's Club app has been updated to the latest version. Outdated apps can sometimes cause functionality issues. You can do this by going to the App Store, searching for Sam's Club, and checking for updates.

2. Check Network Connection: Make sure your iPhone is connected to a reliable Wi-Fi or cellular network. If the connection is weak, trying moving to a stronger network.

3. Clear App Cache: Sometimes clearing the cache can help fix launching issues. Although iOS doesn't allow manual cache clearing, you can achieve this by deleting the app and then reinstalling it from the App Store.

4. Permissions: Ensure the app has all necessary permissions, particularly for camera and location, since these are often crucial for 'Scan and Go' features.

5. Reinstall the App: If none of the above steps work, try uninstalling and reinstalling the app. This will ensure you’re working with a fresh install, free of corrupted files or settings.

If the problem still persists after these steps, you might encounter a specific issue that might require technical support from Sam’s Club directly. You can find more troubleshooting steps or contact support for further assistance.

Please let me know if these steps resolve your issue or if there's anything more I can do to help!