If Streamlit allows for sharing via an embed code, that might provide the easiest way to have it used from within Canvas. Then you could just make a page on Canvas and insert the embed code via either the Insert menu or the HTML Editor.
If Streamlit does not have an embed option, but does have an option to create a share link (meaning anyone clicking on the link is taken to an instance of Streamlit that allows them to use the app), then you just need to place that link on Canvas where desired and let students click on the link.
If Streamlit has neither, then you will want to look at some form of hosting option. Does your institution have the ability to let instructors have a page, then you need to see if it would allow hosting of the code such that you could have students visit that page and use the app. Otherwise, look at some free hosting services like Weebly/Wix/Google Sites/Etc., or acquire their own.