Hi there, dchung. Welcome to the Community, it's a pleasure to have you here.
I'll help you with setting up your company file to function with the new version you're using. To use it with QuickBooks 2020, you'll initially need prepare it for the upgrade. Here's how:
1. Open it in the original version you've been using.
2. Press F2 to bring up the Product Information window, then look for the File Information section. This area will show you where it's saved on your computer. You'll want to take note of where it's located for the next set of steps.
3. Preform a rebuild on it. This is required for it to work in the new version.
The company file will be ready for the next part when you complete the rebuild. Please be aware that once you do this, you'll no longer be able to open it in the older version. Here's the steps to upgrade:
1. Make sure that all users are logged out of QuickBooks.
2. Open the new version and go to File, then Open or Restore Company.
3. Choose Open a company file and hit Next.
4. Browse your computer and select the one you want to upgrade. Once it's selected, Open it.
5. Sign in as an admin user.
6. Select Update Now to start the process. When it's finished, click Done.
Now you'll be able to open your existing file in your new version of QuickBooks and use it as needed. I'll additionally leave this informative article for you: What’s new in QuickBooks Desktop 2020
If you have any other questions, just let me know. I'll be here to help.