LaTeX.org

You are using the glossaries option nogroupskip.
What does it do?
I can't test right now.

Hi and welcome to the forum.

Crosspost
https://tex.stackexchange.com/q/538187/37907

And the page i linked to? You seemed to have read it.

It should be a step by step by step by step walkthrough to getting a bibliography.

Bibtex and biber...
Do you see the difference?

Did you run biber?

Welcome to the forum. Why are you using yhe code you are using? Where does it come from? Some template? You are telling LaTeX/BibTeX twice to use different bibliography styles, that is an error. Why are you redefining the biblabel? Do you know what it is or does? Apart from different styles, i bet y...

Springer will do the typesetting, they just want the content from you.

Commands with the @ symbol are special. You need to activate expert mode to use them.

But really, Springer is in charge of styling your contribution. Your contribution is the content.

Fonts are usually embedded in the pdf by default.

Helvetic is a package that shouldn't be used anymore, really.

Have you thought about using tgheros?