Where should I position CTA or link for finishing chat conversation?

The "Zavrsi" underlined link in the bottom right corner of the screen takes the user to a feedback section, clicking that link should end the chat too. Where should I put that link/button? There will be messages in the left side from customer support. Also I cant add that button to the header of chat, because I have a logo and a button to close the chat modal. "Napisite Vasu poruku" is a placeholder for input field.