Li,
If I understand correctly, I had a similar question - and produced a solution with mixed benefit. The challenge I had was how to find when a particular LTI, installed at the account level, was enabled or used in a Course context. That is, added to the navigation, to an assignment or module, etc. The approach I arrived at was a script that walked through all the Course Shells and looked for external tools in each course in turn, using the APIs for Tabs, Modules, Assignments (maybe another api too.. forgetting here). The beast worked, but was slow when walking through the many thousands of courses in our Canvas. Ultimately the way to do this more efficiently may be to use the Canvas Data Portal to query warehoused data, avoiding all the Rest calls required. But I have not done anything along this line yet. Happy to discuss further if this is the functionality you are interested in. I need to pick up this work someday soon.
Mike