From what I can tell from that image, the LEX could be just about any sans serif. The R is either customized from a sans serif that otherwise matches the width (so an expanded style or stretched horizontally), or the R from a font such as this one.

https://www.dafont.com/01digitall.font?text=LEXR

But if you used that R character, then the stem widths of whatever sans you used may need altered to match that of the R. So unless you actually need a font, I would just customize an existing sans' R that otherwise matches.