PayPal Express custom field problems

I have been messing around with Paypal Express for woocommerce and I have a question.
In the normal checkout page at silverliningherbs.com, I added a custom field that is required on checkout. The field is “How did you hear about us?”. I added it by using the steps in this post
https://docs.woocommerce.com/document/tutorial-customising-checkout-fields-using-actions-and-filters/
Under the section titled “Adding a custom special field.”

The problem I am having is that this field does not show up for users that uses Paypal Express to checkout. However the field is still required. So the user cannot finish their order using Paypal Express because they cannot fill out the required custom field.
I know that I could make the field not required but I not sure if I want to do that.
So my question is. Is there a way to make the custom field show up on Paypal Express so customers can fill it out?
Or is there a way to make the field require on normal checkout but not required on Paypal Express checkout?
Either option would be great. Thank for the help.