FunnelKit Funnel Builder offers you the collapsible optional fields on the checkout page.
By enabling this functionality, you can collect additional data from shoppers without overwhelming them with a long checkout form.
For example, you can provide a collapsible optional field for users to enter their apartment number and floor for a frictionless order fulfillment process.

FunnelKit lets you use any fields as collapsible optional fields.
All you have to do is drag and drop the particular field into your checkout form from the Fields section.
Let’s say you want to know their date of birth for your marketing campaigns. So, first, we’ll add the DOB field to your checkout form.

Then, head to the Optimizations section and enable the Date of Birth field from the Collapsible Optional Field.

Click on ‘Save Changes’ and this will display the DOB field as collapsible on your checkout page.
This is a great way for users to add their information, keeping the overall checkout form concise in length.