You can create a quick assessment for your site without an account. To do so, go to https://www.beam.solar/#get-started and enter the address. Wait for the auto-complete to appear and click on the correct address. The Submit button should now be available.
Once you are redirected to the platform, you will see a banner on top with a Sign Up button.
Enter your email address and click the Sign Up button. A link with an invite to join the Beam platform will be sent to you.