Read more here about loading of the additional font using CSS https://css-tricks.com/snippets/css/using-font-face/
First of all, you need to load the font using @font-face rule and then use the next CSS rule to apply it for the necessary elements like body.rtl p, .rtl h1, .rtl h2, .rtl h3, .rtl h4, .rtl h5, .rtl h6, .rtl .products-title etc
