Examples of websites using
IBM Plex Serif
(IBM Plex Serif is a serif font designed by Mike Abbink of Bold Monday. The font family consists of multiple styles, including regular, bold, italic, and bold italic, offering a range of options for designers and typographers)
with
IBM Plex Sans
(IBM Plex Sans is a Sans Serif font designed by Mike Abbink of Bold Monday. The font family consists of multiple styles and variations, including regular and italics, and is available in a range of weights)