POSIX Queue Message Using fork() function

Question

I am trying to create 2 processes ( client and server) through the fork() function and using the POSIX message queue to exchange messages. When I compile the client and server separately I have no issues and I get the results that I want. However, when I try to combine both the client and the server in the main function I get an error and nothing compiles. I am not sure if it's even possible to use fork() and POSIX message queue together in the main function.

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include <fcntl.h>
#include <mqueue.h>
#include <sys/stat.h>

#define MQ_NAME "/mq_cola_queue"

typedef struct {
    char msg[80];
}Message;


__pid_t wait();

int main (int argc, char* argv []) {
    


    int id = fork();

    // parent process (server)
    if (id == 0) {

        struct mq_attr attributes = {
                .mq_flags = 0,
                .mq_maxmsg = 10,
                .mq_curmsgs = 0,
                .mq_msgsize = sizeof (Message)

        };

        printf("Hello from parent.\n");
        wait(1);


        mqd_t queue = mq_open(MQ_NAME, O_CREAT | O_RDONLY | O_NONBLOCK, S_IRUSR | S_IWUSR, &attributes);

        Message msg;
        mq_receive(queue, (char *)&msg , sizeof(msg), NULL);



        mq_close(queue);
        mq_unlink(MQ_NAME);

        return EXIT_SUCCESS;

        


   // child process (client)
    } else {


        struct mq_attr attributes = {
                .mq_flags = 0,
                .mq_maxmsg = 10,
                .mq_curmsgs = 0,
                .mq_msgsize = sizeof (Message)

        };
        printf("Hello from child.\n");

        mqd_t queue = mq_open(MQ_NAME, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR, &attributes);

        Message msg;
        strcpy(msg.msg, "This is my first message.\n");

        mq_send(queue, (char *)&msg, sizeof (msg), 1);
        /* wait for input to end the program */
        fprintf(stdout, "Press any key to finish\n");
        getchar();

        mq_close(queue);
        mq_unlink(MQ_NAME);

        return EXIT_SUCCESS;

        
    }

    return 0;
}