documentclassarticle}

usepackage[backend=biber, style=authoryear]{biblatex}
addbibresource{biblatex-examples.bib}

DeclareSortingNamekeyScheme{
  keypart{
    namepart{given}
  }
  keypart{
    namepart{prefix}
  }
  keypart{
    namepart{family}
  }
  keypart{
    namepart{suffix}
  }
}

DeclareNameAlias{sortname}{default}

begin{document}
cite{sigfridsson,worman,geer,cicero,nussbaum,knuth:ct:a}
printbibliography
end{document}

DeclareNameAlias{sortname}{first-last}

(/usr/share/texlive/texmf-dist/tex/latex/biblatex/biblatex.cfg
File: biblatex.cfg
)))
! Undefined control sequence.
l.5 DeclareSortingNamekeyScheme
                                {
The control sequence at the end of the top line
of your error message was never def'ed. If you have
misspelled it (e.g., `hobx'), type `I' and the correct
spelling (e.g., `Ihbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

! Undefined control sequence.
l.6   keypart
              {
The control sequence at the end of the top line
of your error message was never def'ed. If you have
misspelled it (e.g., `hobx'), type `I' and the correct
spelling (e.g., `Ihbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

! Undefined control sequence.
l.7     namepart
                 {given}
The control sequence at the end of the top line
of your error message was never def'ed. If you have
misspelled it (e.g., `hobx'), type `I' and the correct
spelling (e.g., `Ihbox'). Otherwise just continue,
and I'll forget about whatever was undefined.


! LaTeX Error: Missing begin{document}.

See the LaTeX manual or LaTeX Companion for explanation.
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