When creating any type of test, on the right side of the top menu of the test edition, you will find the Start… button.

This can only be clicked when you have completed all the minimum information necessary to initialize the test:
- It has a title
- The original element to test has been specified,
- At least one conversion action has been defined.
Note that it is not mandatory to define variant to test since by default, an A/A test is created (a test with a variant that is a copy of the control or original element to test).