Hi there!

Thanks for your query.

Autoresponder is not available with SP Page Builder form addon as there is no default way as per my knowledge.

But if you need multiple recipients to receive the email then you can check the following tips of form builder:

https://www.joomshaper.com/documentation/sp-page-builder/sp-page-builder-3/how-to-tips#how-to-set-multiple-recipients-in-form-builder-addon

Have a nice day!