Hello @Vinh_Nguyen
First of all, your image should be at the following path /ui-builder/containers/default/styles/image.jpeg
Also, your image must not contain quotation marks.
.bg_theme {
background-image: url(image.jpeg);
background-repeat: no-repeat;
background-size: cover;
}
Don’t forget to specify the bg_theme for the classes value for the required block.
Regards,
Inna