Your parent tax number is on their tax return. The schools will require you to link to the IRS data retrieval tool…and they will, therefore, have your parents’ SSNs. Of course, I think to link, they have to provide at least part of their SSN.
As noted above…without all the required information, you won’t get any aid…at all.
If you lied and said your parents had no SSN, you need to fix that.