Add DKIM record for domain using Google MX

I would like to add DKIM record in dns zone some domain deployed on my server. After click DKIM button I see fields: Public-Key, DKIM-Selector, TTL, Active. Of course I know about TTL and Active but where to get Public-Key and DKIM-Selector?

 

enable dkim for the mail-domain and generate a key-pair?

 

I have mail service for this domain deployed on G Suite. There is domain and mail accounts.

 

I did it earlier but thank you for the link. Now I am clear in this case.