I want categorical approach to the notion "transition functions of fiber bundle".
I have found the page https://ncatlab.org/nlab/show/fiber+bundle#definitions in nLab.
According to this page, Fiber bundle has "transition morphisms"$g_{\alpha,\beta}$ as transition functions.
But the difinition of $g_{\alpha,\beta}$ is omitted as a phrase (diagram to come) in the page.
How do we define the "transition morphisms" $g_{\alpha,\beta}$ $??$
Please give me opinions $!!$