macbook pro 2016 keyboard not working

First, let’s see if this issue happens in Safe Mode:

1. Shut down your Mac.
2. Press and hold the power button on your Mac. As you continue to hold the power button, your Mac turns on and loads startup options. When you see Options, release the power button.
3. Select your startup disk. It's named Macintosh HD, unless you changed its name.
4. Press and hold the Shift key, then click the “Continue in Safe Mode” button below your startup disk.
5. Log in to your Mac. You might be asked to log in again.

If the strange behaviors do not occur, then it may possibly be a software issue.

If the issue doesn't continue in safe mode:

Leave safe mode by restarting your Mac normally, then try to reproduce the issue.

If the issue doesn't return, it might have been resolved by the other things that safe mode did at startup, such as checking your disk and clearing caches.

If the problem persists, then let’s try this:

• Software Update.
• Use Apple Diagnostics to test your Mac.

If none of those ideas work, then I recommend service.

Service Checklist:

• Mac service pricing.
• Check AppleCare Coverage.
• Get your Mac ready for service.

Click ▶︎ Start a Service Request. ⚛️

Need more help?

• Call 1-800-APLCARE.
• Contact Support.
• Mac Support.
• Mac User Guide.

Click ▶︎ Check Repair Status. 🔧

Good luck! 👋🏼😉

That is a known failure with those butterfly keyboards used on the 2016-2019 models. Apple did have a free repair program for the issue, but it expired long ago.

The best you can do is hope the issue is due to dirt & crumbs beneath the keys.....here is an Apple article for cleaning the keyboard. Make sure to keep the can of compressed air completely upright or you may damage the laptop with the cold wet propellant. If the issue is not with dirt & crumbs, then you will need to use an external keyboard instead since your laptop is Obsolete which means no Apple repair is possible (it would not be worth it anyway for such an old system with several known design & manufacturing flaws).

How to clean the keyboard of your MacBook or MacBook Pro - Apple Support