Go to https://cobuilder.com/en/cobuilder-collaborate/ and click  Register:

Fill in your company's details and click Next:

Proceed with filling in the company address. Click Next:

You will then be asked to fill in your contact details and confirm that you have read and agree to our Terms and Conditions. Click Register when finished:

A pop-up window will appear promting you to give your consent to the new rules about protetion of personal data:

You have now completed the registration form. Shortly, you will receive an e-mail with activation link: