So, I wanted to make the name of the chatbot in the header stand out more. Therefor I’ve added to the CSS code to load a font type from Google Fonts to apply only to the header text and made the text bold as well.
To do yours just (1) replace the URL in the example with the URL of your prefered font and (2) change font-family name to match the family name behind the = in the URL.
@import url("https://fonts.googleapis.com/css2?family=Lexend:wght@300;500;600;700&display=swap");
[class*="window-header__Title-sc"] {
font-family: 'Lexend';
font-weight: bold;
}