There is nothing fancy there. Just

"%{fetch-bibtex}* TODO %?%(org-capture-ref-get-bibtex-field :title)"
":PROPERTIES:"
":ID: %(org-capture-ref-get-bibtex-field :key)"
":CREATED: %U"
":END:"
"#+begin_src bibtex"
"%(org-capture-ref-get-bibtex-field :bibtex)"
"#+end_src bibtex"

> 2. When you write that there is support for Google Scholar "BiBTeX page",
> what do you mean? In a Google scholar search, if I click "Cite" and then
> choose BiBTeX, I don't get the expected result, but maybe you are referring
> to something else?

I am referring to what you said: "Cite" → "BibTeX". The opened page
should contain the BibTeX entry text. This page can be captured.

For example, the first item (Cite → BibTeX) in
https://scholar.google.com.sg/scholar?q=test

can be captured on my side.

I do not recommend this method though. Google Scholar does not provide
high quality BibTeX entries with DOI and sometimes provides plain wrong
entries.

#+begin_src bibtex
@article{algozzine2001effects,
  title={Effects of interventions to promote self-determination for individuals with disabilities},
  author={Algozzine, Bob and Browder, Diane and Karvonen, Meagan and Test, David W and Wood, Wendy M},
  journal={Review of Educational Research},
  volume={71},
  number={2},
  pages={219--277},
  year={2001},
  publisher={Sage Publications Sage CA: Thousand Oaks, CA}
}
#+end_src bibtex