If you are using Trello, you can import all the Projects, Task lists, Tasks, Subtasks, and even Users into the WP Project Manager.
This feature is completely free! All you have to do is to collect a token and an authentication key from Trello. Follow these steps to connect Trello to WP Project Manager:
After signing in to your Trello account, click on this link. You will see the following screen:
Check the box and click on the Show API Key button.
Now, you will get the developer API key. Now, click on the ‘Token' option to get the token key.
Next, click on the ‘Allow' button.
Finally, a new page will pop up showing you the token key:
Now navigate to the WP Admin Dashboard > Project Manager > Tools. Copy and paste the API key and the token key. Finally, hit the Imports button.
You will see that the Project Manager is importing the tasks from Trello.
After successful importation, you will be able to see the Trello projects along with the existing projects. Go to the WP Admin Dashboard > Project Manager > Projects to check whether the projects have been imported or not.
That's how you can import projects from Trello to the WP Project Manager.
Have a look at this video.