how to get the cited references

[Wolfgang Engelmann]

I need the cited references from a document (Koma script, book A5, 
Luatex). I use Debian Bullseye and Jabref 5.6 as a reference manager 
(LyX see below).

The bib file contains much more citation.
I used to export the .tex file of the document and to run latex thrice. 
However, I am using now luatex and running luatex MyDocument gives many 
errors such as

(./A-SP-WITTE-E-2023Apr13.tex
! Undefined control sequence.
l.3 \documentclass
                 [paper=a5,ngerman,british]{scrbook}

! Undefined control sequence.
l.4 \usepackage
              {amstext}
?
! Undefined control sequence.
l.5 \usepackage
              {amssymb}

! Undefined control sequence.
l.6 \usepackage
              {fontspec}

! Undefined control sequence.
l.7 \setcounter
              {secnumdepth}{3}

it does not produce an aux file which I would like to refer to in Jabref 
in order to get the cited references.

I use LyX Version 2.4.0-beta2
OS-Version (bei Erstellung): Debian GNU/Linux 11 (bullseye)
Python-Aufruf: python3 -tt)

Could somebody tell me how I should proceed? I would very much 
appreciate it!

Wolfgang