%lex-param is not working

In the bison source file I have
%lex-param { ps->scaninfo }

When I compile the parser I get:
parser.tab.cpp: In function ‘int yyparse(parse_state*)’:
parser.tab.cpp:1689:41: error: ‘scaninfo’ was not declared in this scope;
did you mean ‘scanf’?
 1689 |       yychar = yylex (&yylval, &yylloc, scaninfo);

The 'ps->' is missing.

Is this the correct use of %lex-param? Is there a better way to specify the
parameter?

Thanks for your time and consideration?

Tim