I'm not sure what you are trying to do, but here is one way you could do it.
When the LTI app is integrated into the course and placed in the Course Navigatoin, there will be a button or link exposed somewhere in the course itself, maybe in the left course menu or possibly in the right menu panel.
The simple solution is to inspect the HTML of that LTI application button and get the link information, and use that information to build your own button on your content page. I have tested this and it will work.
One obvious gotcha, if the LTI app is integrated for admin or faculty only, and you are trying to expose it for students, you will not get the result you want if the LTI provider is doing their job properly and inspecting the user roles.
I suppose one advantage to doing this is that you could remove the LTI app from the course navigation, so students would only see the LTI button on the pages that the LTI functions are related to.
Can you share the use case that you have in mind for this?