To sign up for fucimo as an ad seller, you must first sign up as a user using one of the available methods:

1. Visit the fucimo website and enter your work email address, then click "Continue."
2. Alternatively, you can log in using your Google, Facebook, or LinkedIn account by clicking on the corresponding "Continue with" button.

After logging in as a user, you can then proceed to register as an ad seller by providing the required information and completing the verification process.