In TurboTax Online there is no way to print a form that is not part of your tax return. The lender is being unreasonable. They are probably working off of a checklist without any knowledge of the rules for tax returns, and without applying any logic. Schedule 1 is not used, and there is no reason to look for Schedule 1, if both line 8 and line 10 of Form 1040 are blank or zero.
You could try asking to speak to someone who is more knowledgeable about tax returns. Or you can try to satisfy them by downloading a blank Schedule 1 from the IRS web site. Print the form, fill in your name and Social Security number at the top, and give the lender the blank Schedule 1. Maybe that will make them happy.