Well lucky for us, the book is so old that it’s long out of copyright, and additionally, the screenshot includes a precise location within that book (6.65, likely referring to Book 6, paragraph 65).

Here’s the book:

https://en.wikisource.org/wiki/Lives_of_the_Eminent_Philosophers/Book_VI#Diogenes

Please verify for yourself that paragraph 65 does indeed relay the same story as presented above, so that we can all be safe in the assumption that “he” in that paragraph does indeed refer to Diogenes of Sinope, not Diogenes Laertius.