Hi! I understand you’re having trouble with the Engage app on your Mac running OS X 10.15.7 where you can’t type anything or interact with it. Let’s try to narrow down the cause together.

First, a couple of questions to better understand the issue:
- Does this problem happen only in Engage, or are other apps affected as well?
- Have you tried quitting and reopening the Engage app, or restarting your Mac already?
- Are you connected to the internet, and has the connection been stable?

Meanwhile, here are some initial troubleshooting steps to try:

1. Force Quit and Reopen Engage:
- Press Command + Option + Escape to open the Force Quit window.
- Select Engage and click Force Quit.
- Then open the app again.

2. Check for Updates:
- Make sure Engage and your macOS are up to date. Sometimes app bugs can cause input issues.
- Since you are on 10.15.7, check in the App Store for Engage updates.
- Check System Preferences > Software Update for macOS updates if available.

3. Confirm Keyboard Input:
- Open a simple app like TextEdit and confirm that your keyboard input works there.
- If it doesn’t, the problem is likely with macOS or the keyboard, not Engage.

4. Internet Connection:
- Engage requires an Internet connection. Try visiting a different website or opening other Internet-based apps.

5. App Permissions:
- Sometimes, apps need permissions to access input devices.
- Go to System Preferences > Security & Privacy > Privacy tab.
- Check under Accessibility and Input Monitoring that Engage is allowed.

If these don’t help, there could be a locked input mode or a temporary freeze in the app. Also, clearing the app cache or reinstalling Engage might help.

Let me know what you’ve already tried with these, and any additional details about the behavior you see. We’ll get this sorted out!