You can set/reset your password using the following URL: https://apps.atinternet-solutions.com/login/#/remind
Please fill in the dedicated form and in the following minutes of your request click on the new activation link sent by e-mail to set your password.
Please note that the password activation link has a lifetime of 24h to avoid potential intrusions to your account. If the link has expired before you could set up the password, simply follow the same process again.