Headers / Footers in Libre Office

Hi all

I ahve a question about modifyng headers/footers in libre office so thought to ask it here.

I have a 25 page document, now what I want is I should have 3 differnt headers as per the following:

Page 1 - 10 should have a header “Welcome”

Page 11 - 20 should ahve a header “introduction”

Page 21 - 25 should ahve a header “conclusion”

How do I make this possible?