Hi,

Please go to Appearance → Customize → Custom CSS then add the following custom CSS code:

.home-featured-boxes ul.homepage-featured-boxes:before {
  content: 'This is a heading text';
  display: block;
  text-align: center;
  margin: 0 0 30px;
  font-size: 22px;
  line-height: 1.2;
  font-family: var(--pchead-font);
  font-weight: var(--pchead-wei);
}

Regards,
PenciDesign.