error: Missing number, treated as zero. question

documentclass[addpoints]{exam}
%==============================================================================
usepackage[bidi=basic,layout=sectioning.tabular,english]{babel}
usepackage{unicode-math}

babelprovide[import,main]{arabic} % You might select a variant here.
babelprovide[onchar=ids fonts]{english}

defaultfontfeatures{ Scale=MatchLowercase, Ligatures=TeX }
babelfont{rm}
[Scale=1.0, Ligatures={Common,Discretionary}]{Libertinus Serif}
babelfont[arabic]{rm}
{Amiri} % Might want to load a stylistic set or activate font features.
babelfont{sf}
[Ligatures={Common,Discretionary}]{Libertinus Sans}
% Load a sans-serif Arabic font here if needed, for example Noto Sans Arabic.
babelfont{tt}
{Libertinus Mono}
babelfont[arabic]{tt}
{ALM Fixed}
setmathfont{Libertinus Math}
babeltags{Arabic=arabic} % Enable Arabic, textArabic, etc.
babeltags{english=english}
%==============================================================================
begin{document}
pagestyle{headandfoot}
firstpageheader{bfserieslarge رياضياتمأمون }{}{bfserieslarge الإمتحان الأول }

gradetable[h][questions] 

begin{questions}
    question السؤال الأول:
end{questions} 
    
end{document}
%==============================================================================