Login does not work on OpenBSD

[unix-world]

This specific code does not work, from pam.c:

    int result = pam_start(SERVICE_NAME, username, NULL, &pam_handle);
    if (result != PAM_SUCCESS) {
		printf("err %d", result);
        err("pam_start...");
    }

It always return:
pam_start: System error

I have checked and the openpam-20200510p0 is installed in my computer, OpenBSD 7.3 amd64