Vocareum supports LTI 1.1 as a producer. Go to your course and select Settings which take you to the page where all the course specific parameters can be set. Turn LTI to ON to indicate to Vocareum that you intend to integrate this course to a LTI consumer. Option "Show all assignments" should be OFF if you want Vocareum to only show the assignment that the student clicked on in their LMS. If ON student can navigate to other published assignments from their Vocareum window.
Click on "LTI details" to get the "Secret", "Key". These are automatically created by Vocareum and you will need this information in your LMS setup to record Vocareum as LTI producer.
Under Options for the assignments you will see launch URL for that assignment.
Follow the instructions provided by your LMS on how to use the Secret, Key and Launch URL to indicate LTI 1.1 producer.