Place Search form in header image

Hello again, in your theme Demo you have your Search form in the header image at the bottom of the image. How can I do that?
http://preview.themeforest.net/item/travelwp-traveltour-booking-wordpress-theme/full_screen_preview/19029758?_ga=2.77301077.1165991740.1552015449-1299626957.1552015449

Our home page I don’t know how to set the search bar inside the top image https://www.phuketdreamcompany.asia/