If you are editing the lesson you want to test, there is a 'Teach' button at the top right of your screen. If you click on this, you are teaching a live lesson and can join the lesson using the unique code that appears at the bottom left of your screen.

Go to lessonup.app in a new tab or on your phone and enter the lesson's pincode. This way, you can see what students see when they join your lesson.

Don't forget to close the lesson when you are done testing.

With your teacher login details, you can log in directly to the student environment via the site lessonup.app.

Then add yourself to one or more classes. You do this the same way as a student: via the classcode (via: My Classes).

In your student environment, the classes and subjects you have been added to as a student will now appear. This looks something like this:

Click on the class you want to test and walk through it. This way, you have a better grip on shared learning and can quickly spot any errors (e.g. in a test).