Pin message in supergroups

Forgive me if it's something that I need to learn from telegram api myself, but I wonder how can I pin a message in supergroups using this method:

https://core.telegram.org/bots/api#pinchatmessage

How can I get id of my chat to pin it?

And further just pin it if it's a problem and when it gets resolved unpin message using this method:

https://core.telegram.org/bots/api#unpinchatmessage

Of course I have administrator rights in the group.