Building Department Preliminary Steel Affidavit

Has anyone ever encountered this affidavit from the DOB, https://www1.nyc.gov/assets/buildings/pdf/b_form_20_ss.pdf ? The building department is asking us to provide this for a small project with one piece of Steel. Contractor was planning on buying the steel and installing it themselves therefore their supplier won’t sign this. Anyone have any suggestions on how to get this waived by the DOB. Thanks.