If you wish to join an existing organisation you can do so in two ways:

1. Your email address is in the organisation’s domain.
   Create your account via the registration form available at checly.app/register and then – when logging in for the first time – select the name of the organisation you wish to join from the list. If your Organisation admin has allowed any user with an email address in the organisation’s domain to join, you will be able to do so automatically. If not, the Organisation admin will need to permit you to do so.
   
2. Your email address is not in the organisation’s domain.
   In this case, ask your Organisation admin to create an account for you in the application. You will be notified of this in an email. Once a new password for your account has been set, you will automatically be redirected to the organisation’s Dashboard.

Check also

What is the “Allow anyone from the domain to join the organization” feature?

How do I add a new user to the organisation?