Address on confirmation message is wrong

If WordPress is installed in sub directory and “site address” is set to root,
Address on confirmation e-mail message will be:
http://***.com/wp/

but it should be
http://***.com/

You should use get_home_url() instead of get_site_url() in mailjet-widget.php

https://ww.wp.xz.cn/plugins/mailjet-for-wordpress/