Pro*c compliation error "unknown type name VARCHAR"

Question

Getting below "error: unknown type name ‘VARCHAR’" when compliing Proc*c code.

DEV >>:make
EIOO
CLEAN:
path/to/c/file/exe/xxxx
path/to/c/file/obj/xxxx.o
path/to/c/file/obj/yyyy.o
path/to/c/fileo/pc/yyyy.c
COMP: /path/to/c/file/xxxx.c
In file included from /path/to/c/file/xxxx.c:63:
/path/to/h/file/xxxx.c:54:8: **error: unknown type name ‘VARCHAR’
 static VARCHAR  evcRowid[21];**
        ^~~~~~~
compilation terminated due to -Wfatal-errors.
make: *** [/src/billmill/make_include/mk_alku_vtuotanto:125: /path/to/c/file/xxxx.o] Error 1
virhekoodi 2
DEV >> :

My below are content of my pcscfg.cfg.

DEV >>:cat /usr/lib/oracle/19.10/client64/precomp/admin/pcscfg.cfg
sys_include=(/usr/include/oracle/19.10/client64,/usr/include,/usr/lib/gcc/x86_64-redhat-linux/8/include)
ltype=short
define=__x86_64__
define=_MATH_H

DEV >>:

/path/to/c/file/xxxx.c includes below all header files from Oracle DB client.

#include <oro.h> 
#include <oci.h>
#include <ociap.h>
#include <oraca.h>
#include <orid.h>
#include <ori.h>
#include <oratypes.h>
#include <ocidfn.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sqlda.h>
#include <sqlcpr.h>
#include <sql2oci.h>
#include <sqlca.h>

I'm using Oracle DB instant client 19.10. Referring post I tried using VARCHAR2, still same error....

How can I get VARCHAR ad valid datatype for Proc*c code with Oracle DB instant client 19.10? OS: RHEL-8 and gcc version 8.5.0 20210514 (Red Hat 8.5.0-16) (GCC).