Hello @Ilon Choai7! To make sure the same font getting displayed on the mobile devices, you need to include the proper <link> tag in the end of <head> tag. Please go to Theme> Advanced Settings tab and insert it under Code added to the end of <head> tag section.
e.g. <link href="https://fonts.googleapis.com/css?family=Source+Sans+Pro:400,6003" rel="stylesheet">