private questionaires to customers - how to do that in Zoho?

private questionaires to customers - how to do that in Zoho?

Hi,

For a business idea we're exploring, I'm looking at how to give customers a tailor-made questionnaire, kinda like private.
Zoho would be a great platform for the other parts of this idea, but as far as I know, you can't send a private form to a non-user. And I don't want to load all customers as user on zoho.

Are there other solutions to explore?

Best,
Menno