Create a lead without login partner portal

Hi,

I've created a lightning form to capture input from customer and create a lead with the captured data and deployed it in a partner portal community.

But the issue here that I'm facing is, if I login to partner portal and fill up the form, I'm able to create a lead.

If I'm not logging into the partner portal, and fill the form (made it publicly available) and submit, it is not creating a lead.

please let me know what setting I'll have to change to create a lead from the form, though the user is not logged in.

Thanks,
Rakesh