You can install a custom App, which Alexander Street has developed to work with, in Canvas's settings either manually: https://community.canvaslms.com/docs/DOC-13135-415257103
or by using XML: https://community.canvaslms.com/docs/DOC-12863-415274552.
Alexander Street's XML config is located here: https://search.alexanderstreet.com/lti/config.xml. Currently, an LTI App is not available in the Edu App Center, this is being evaluated for future enhancement.
If you do not know your LTI Consumer Key and Secret, please contact technical support for assistance.