Hello,

I saw the screenshot you attached.

Please try adding the following Custom CSS in the Global Custom CSS area under Theme Settings >> Custom CSS.

span.prdctfltr_widget_title {
	font-size: 24px;
    font-weight: 700;
}

.prdctfltr_filter label {
	font-size: 18px;
    font-weight: 400;
}

You can set the font-sizes and weight according to your needs.

Regards.
Xtemos Studios.