[Theme – Mercury] Not responsive on mobile devices

can someone please help me with the below?

my website is currently not responsive and not appearing correctly at all on tablet (e.g., ipad) or mobile (e.g., smart phone) devices

it is appearing fine on Desktop however, with some minor bugs

what’s going on here? how do i fix it?

thanks,

theme i purchase – https://themeforest.net/item/mercury-responsive-portfolio-photography-theme/6207813
website – https://travelmolecule.com/