This question already has an answer here:
I know how to use
\LaTeX to get a fancy version of the word LaTex; I’ve seen a similar version of the spelling of BibTeX but
\BibTeX doesn’t work. I’ve tried a few variants on capitalization and not hit on one that works.
The problem with searching about anything to do with BibTeX is there are so many articles on how to use it that this specific question does not show up in queries.
It ought to be possible to do this: