WordPress plugin shortcodes not outputting anything

Question

wp_remote_get doesn’t return a string, it returns an array, and if we refer to the documentation:

$response = wp_remote_get( 'http://www.example.com/index.html' );
if( is_array($response) ) {
  $header = $response['headers']; // array of http header lines
  $body = $response['body']; // use the content
}

Here $response would not be a json string, but an array containing the headers and a body, the body containing a json string.

So:

function mcq_getMcApi($type){
    // This function mcq_gets the information from "mcapi.ca" if required
    $json = wp_remote_get("https://mcapi.ca/query/$ip/$type");
    return json_decode($json,true);
}

becomes:

function mcq_getMcApi($type){
    // This function mcq_gets the information from "mcapi.ca" if required
    $response = wp_remote_get("https://mcapi.ca/query/$ip/$type");
    return json_decode($response['body'],true);
}

Note that wp_remote_get will return a WP_Error object that you should check for it any of this fails, and you should check the response, as it may not be a json string.