Instead of keeping copies of files and notes in my task manager, I much prefer to add links to these resources in the task title or description.
For example, file:///xxxx, evernote:///view/957/s1/c3147882-03ba-4b77-843a-ca2e706aaa8d/ or obsidian://open?vault=Life&file=Cryptocurrency%20Education.md.
Todoist handles these links perfectly.