Error with rewrite rules

There’s an error with the rewrite rules.
In function sendinblue_woocommerce_rewrites in file woocommerce-sendinblue.php on line 146, the rewrite rule is added inside an array, which is not valid.

Instead of:

$wp_rules[] = array(
    "sendinblue-callback\$" => 'index.php?pagename=sendinblue-callback'
);

write this:
$wp_rules[ 'sendinblue-callback\$' ] = 'index.php?pagename=sendinblue-callback';