how do i initialize user_in_list while trying to make it take the value of the parameter
int create_user(const char *name, User **user_ptr_add) {
    User *user_in_list = *user_ptr_add;
    if(strlen(name) >= MAX_NAME){
        return 2;
    }

    User *null_ptr = NULL;
    
    while(user_in_list != null_ptr){
        if(user_in_list->name && strcmp(user_in_list->name, name) == 0){
            return 1;
        }
        else{
            user_in_list = user_in_list->next;
        }
    }