As admin, enable "Mobile services": Enable “Web services for mobile devices” on Site administration ► Advanced features Create course, users and assignments: Create a course Create two users (student1, student2) and save the user ids Create one editing teacher (teacher) and save the user id Create two assign modules (assign1, assign2) and save the assign ids Create submissions: In assign1 create submissions for student1 and student2 In assign2 create submissions for student1 As admin, create users tokens: Server ► Web Services ► Manage tokens: Create a Token for teacher and save the teachertoken. Create a Token for the student1 and save the student1token. Create a Token for the student2 and save the student2token. Next, make CURL REST calls simulating a WS client. You need to replace MOODLE_URL and make different calls changing $wstoken, $userid, and $assignid: curl 'MOODLE_URL/webservice/rest/server.php?moodlewsrestformat=json' --data 'wsfunction=mod_assign_remove_submission&wstoken=$wstoken&userid=$userid&assignid=$assignid' --compressed Run the CURL with student1token, student1id and assign1id Confirm that you receive a "true" response and the submission has been deleted on campus. Run the CURL with student1token, student2id and assign1id Confirm that you receive a "false" response, the warningcode is “couldnotremovesubmission” and the submission has not been deleted on campus Run the CURL with teachertoken, student2id and assign1id Confirm that you receive a "false" response, the warningcode is “couldnotremovesubmission” and the submission has not been deleted on campus Run the CURL with student2token, student2id and assign2id Confirm that you receive a "false" response, the warningcode is “submissionnotfoundtoremove” and the submission not exists. Run the CURL with student1token, an non-existing user id and assign2id Confirm that you receive a "false" response, the warningcode is “submissionnotfoundtoremove” and the submission not exists. Run the CURL with student1token, student1id and an non-existing assign id Confirm that you receive an “invalidrecord” exception.