The Sandbox (test) environment is available at any time; you don't need to have an activated account. So you can take advantage of the activation period to start testing!
Create a shop or an application (Developers tab) from your Virement Maitrisé space by selecting the Sandbox environment.
Explore our documentation for the different scenarios you can simulate.
To find your test payment sessions, go to the Payments tab and select Sandbox at the top right of your screen.