One of the requests we've received fairly often is to collect address information on donors. By default, we have this option turned off as it can reduce the amount of donations coming through your site as it adds an extra step for your donors.
If you wish to turn it on you can certainly opt to do so on a campaign by campaign basis!
Go to your campaigns page and find the campaign you wish to create the modal for and click on the Manage action.
Select the Settings tab to dive in and toggle the option on.
Turn the "Collect Donor Addresses" switch on and your campaign page will start collecting addresses automatically!
You can view these addresses when you export your donor data from the donations tab.