A Task needs to be part of an Activity (via being in the Activity issue's task list), or Maintenance or Documentation (marked as labels).
Assign issue to who will be working on it (can be yourself)
Add the Task
label for the issue
GitHub will then add the Task issue to the Tasks project. You may need to refresh the web page. Expand the project section
Select the quarter the Task issue is being worked on (nearly always the current quarter)
For Tasks that are part of an Activity do not set the week.