Examples of websites using
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)
with
PT Serif
(PT Serif is a serif font designed by ParaType. The font family consists of multiple styles, including regular and italic, and is suitable for various projects)