How to eliminate this white space

Hi,

I am using twenty nineteen theme and it seems that every page has a white space after the header image as seen here – https://prnt.sc/lzkhqe

My website URL is here – https://www.nature-health.com/about-us/

May I know how can I eliminate the white space?

Any help will be greatly appreciated, thank you!

The page I need help with: [log in to see the link]