Hello,

Please use this code:

body .page-title-default {
	    background-size: cover;
    background-position: center center;
	background-image: url(https://z9d7c4u6.rocketcdn.me/wp-content/uploads/2021/04/blog-title-bg6-opt.jpg)!important;
    background-repeat: repeat;
}

If you have any questions please feel free to contact us.

Best Regards