https://www.nos.pt/pacotes/testar-cobertura-de-fibra - use this link. Usually support is in english

Hello ​@Yaremchuk Oleg,

Thank you for reaching out to us. 
​@Guimas gave a good assistance. Please let us know if you have any questions.

Thank you

on this link the system shows me availability for fiber by postcode. How can I find out the availability specifically in my address?

Hello ​@Yaremchuk Oleg,

Thank you for your message. 

In the same page you can use the “Liguem-me grátis” button, to ask for a call from a NOS Assistant to help you in the process.

Let us know if you have any questions.

Thank you