"mathastext" --> "setmathfont"

ptbposter/ptbposter-new-engines.clo

@@ -31,7 +31,7 @@
 \else
   \renewcommand*\familydefault{\sfdefault} 
   \RequirePackage[usefilenames,weight=Regular]{firamath-otf}
-  \RequirePackage[italic]{mathastext}  
+  \setmathfont[range=it]{texgyreheros-italic.otf}  
 \fi
 \RequirePackage{newunicodechar}
 \newunicodechar{^^^^202f}{\,}% 'NARROW NO-BREAK SPACE' (\u202F, 8239)