To activate JRebel on IntelliJ, you head to help, JRebel, activation.

In here, you will enter your team URL and the email associated with that team URL.

Click I agree with terms and conditions, and you click change license, and you should see this JRebel activated to confirm that it works.

On this activation page, you can also use a license file.

Here, you will give the path to your JRebel dot license file.

And you click change license, and you should see this active JRebel activated page.

And the last way is to use your activation code, which you should have if you have a trial or evaluation license.

Course - Installing JRebel on IntelliJ IDEA