Hi!
Is there any possibility to invite a user to answer a question? Like here, in Quora:
Yes, use the invite button on the topic.
You must be TL2 to send invites however.
Agree with Jeff, right now @Agnieszka_Jaskiewicz you have TL1 here on discourse.
When you get the TL2, you will see the “invite button” like:

Some off-topic points:
Regards!
Thanks! What do you mean with TL2? What are the next steps when a user gets a request to answer a question? Does he get an email or what?
Search “trust level howto”. Find Understanding user statuses, roles, and permissions
Nossos usuários recebem o TL2 por padrão. Gostaria de manter a opção “convidar para responder” apenas para administradores, pois tenho receio de que os usuários comecem a se spamizar. Como podemos habilitar essa opção a partir do TL3?