You can add tests and surveys to courses by using the Add Test button in the toolbar.

Step 1: Select the module or topic where you want to add the test (or survey) and click the Add Test button in the toolbar (or right-click on any module/topic and select Add Test from the contextual menu).

Step 2: Now you would see a link to select an already published Test or upload Test. Using 'Select an existing test' you can add an existing test to the course. If a test is not yet created, you can upload a new test.

Step 3 A: select an already published Test - You would get a dialog box to choose an existing test or survey; the dialog will show you tests which you own as a user or ones which are owned by a group where you are an admin or instructor. The list would show only those tests and surveys which have been published at least once from the Test Editor.  You can search for a test by name to filter the list. After finding the test you want, select it and click the Select & Close button

Step 3 B: upload Test - You can upload a new test using a Word file. The test will be created and added to the course.

For test upload details, refer to the article - Quiz upload using word template

Step 4  Save and publish: Your selected/uploaded test would get inserted into the course; you can change the properties of the test like the number of attempts and make it mandatory. You can also rename it to something else, which would be its name locally within this course (note that a test can be inserted in more than one course). You can remove the test from the course and add more tests. Once everything looks fine, hit the Save button to save everything.

For details regarding Quiz Properties, refer to support article - Quiz_properties

For generating a test using Course Quizzes questions refer to support article Generate Test