Development and (premium) support is provided by <a href="https://www.webdados.pt">Webdados</a>.
We do not provide free support for this free plugin, but you can submit bug reports here at WordPress.org
You'll get included support if you buy the <a href="https://multicaixa-woocommerce.com">plugin PRO add-on</a>.
For premium support or custom developments, you should contact <a href="https://www.webdados.pt/contactos/">Webdados</a>. Charges may (and most certainly will) apply.