Please go here first to properly configure your LTI settings
From your Canvas Courses navigate to Pages and select "+ Page"
To use the Vocareum Tool select Tools > Apps > Vocareum Editor/HTML
If you run into an issue connecting the Vocareum tool please consult our documentation here
Find the desired assignment and choose whether to use iframe to embed it to the page or add a direct link that opens in a new tab
The Vocaruem assignment should now be visible in the editor
Select Save & Publish