Aigerim, we had exactly this with a landlord who was travelling for two months. A few things that worked for us, in order:
- check whether a property management company handles the building. Ours did, and they were allowed to sign the form on the owner's behalf, which nobody had told us
- phone rather than write. The owner answered on the third call and was happy to sign; he'd simply ignored the post
- if the deadline is close, go to the office anyway with the rental contract and proof that you asked. In our case they noted it and gave us a short extension to bring the form
Your husband isn't wrong. Going and explaining, with evidence that you tried, is the correct way to do it, not a shortcut. They see this every day.