Hello! I understand you're stuck on the "Thank You" screen in the Microsoft NOW app on your Mac running OS X 10.15.7. Let's get this sorted out together.

To start, could you tell me a bit more? For example:
- When exactly does it get stuck on that screen? Is it right after a specific action like signing in or completing a task?
- Have you tried closing and reopening the app?
- Do you have a stable internet connection while using the app?

Meanwhile, here are some initial steps we can try:

1. Force Quit and Relaunch the App:
- Click the Apple menu (top left corner) and select "Force Quit…"
- Find "Microsoft NOW" in the list, select it, and click "Force Quit"
- Reopen the app to see if it moves past the "Thank You" screen.

2. Check for App Updates:
- Open the App Store on your Mac.
- Click on "Updates" in the sidebar.
- See if there’s an update for Microsoft NOW and install it if available.

3. Restart Your Mac:
- Sometimes a simple reboot can clear temporary glitches.
- Click the Apple menu and select "Restart."

4. Clear App Cache (if possible):
- Mac apps usually store cache in the Library folder.
- Open Finder, hold down the Option key, click "Go" > "Library."
- Navigate to Caches and look for any folders named related to Microsoft NOW.
- If found, move these folders to Trash (this won’t delete your data but can clear corrupt cache).

If these don’t help, it’s good to check if your Microsoft account is authenticated properly in the app and if there are any connectivity issues.

Could you please try these and let me know how it goes? If it remains stuck, we can explore advanced troubleshooting.

Are you satisfied with this approach so far?