centOS 7.9 : openssl/ssl.h: No such file or directory

[phpcws]

When installing spansp, an 【 In file included from fax.c:67:0:
spandsp/ssl_fax.h:35:25: fatal error: openssl/ssl.h: No such file or directory 】message appears, but openssl is already installed. Is there anything I need to check?

[root@10-81-28-50 spandsp]# openssl version
OpenSSL 3.0.1 14 Dec 2021 (Library: OpenSSL 3.0.1 14 Dec 2021)

[root@10-81-28-50 spandsp]# whereis openssl
openssl: /usr/lib64/openssl /usr/local/openssl /usr/local/openssl/bin/openssl

[coppice-git]

Do you need to add a -devel (RPM) or -dev (APT) package to your system? The configure.ac file in spandsp was update to check for an SSL package, but maybe its not being thorough enough.