Applications must be submitted online, and for this purpose, it is necessary to make the registration and send the documents mention in the next FAQ - "What do I have to deliver at the time of the application".
Link to the Online Application: Fenix.
The steps to make your application online are described in the document available here (download pdf (PT)).
If you do not have yet a ULisboa Campus account (email address terminated at @ campus.ul.pt) you must first create an access credential at: Fenix - AccountCreation, in this case, fill all fields marked with an *.
If you have difficulties with access, you should contact the ICT Department through the following e-mail address: Este endereço de email está protegido contra piratas. Necessita ativar o JavaScript para o visualizar.