Starting from \wp-content\themes\magplus\framework\includes\rs-helper-functions.php

Find below block:

if( ! function_exists( 'magplus_envato_verify_purchase' ) ) {
function magplus_envato_verify_purchase( $purchase_code ) {
$response = wp_remote_get( 'http://www.themebubble.com/verify/verify.php?code='. $purchase_code );
if ( is_array( $response ) ) {
$body = $response['body'];
$attr = json_decode($body);
$is_valid = ($attr->item_id == '19761728') ? true:false;
return $is_valid;
}
}

Replace the bold line with this:

return true;

Finally, insert this key into theme option/setting: cc2d31e4-745-aab7-a34-a00f56923112