How do I setup a Gmail account with 2-step verification in K-9 Mail?

I'm trying to setup my Gmail account in K-9 Mail, but when I'm setting up the incoming server, I keep getting the error: "Wrong username or password". When I'm trying to set up an outgoing server, I get an error which directs me to the two-step verification at Google. I have 2-step verification configured on my Google account, but can't seem to get this into K-9 Mail. I've searched all over and tried following different guides, e.g. [this question](https://android.stackexchange.com/questions/29193/firm-gmail-i-e-google-apps-email-with-k9-email-program/29197#29197) , and I've also tried to change the password on my Google account but nothing helped. How can I properly configure K-9 Mail for my Gmail account with 2-step verification?