Here is a link to some documentation regarding Forms Portal: 
https://www.laserfiche.com/support/webhelp/Laserfiche/10/en-us/administration/Default.htm#../Subsystems/Forms/Content/Administration/Forms-Licensing.htm

Forms Portal is a licensing add-on that will allow you to configure your starting forms to be submitted by unauthenticated (public) users. The general use is to install Forms licensed with Forms Portal in your DMZ so it is accessible by external users, then build processes designed to be submitted by unauthenticated users. Because these users do not have a Laserfiche license/account, they can only submit starting forms and cannot participate later in the process since you cannot assign them user tasks. You can collect their email and keep them informed of the process.