I’ll let you know how I go. I’m in a similar position, but also in a worse one.
I work for family business and it’s an ordinary partnership so no business reg. - I sent VAT document which had all the same info but not sure if they’ll accept it. (I’m also British so not sure what your equivalent is)
I also didn’t have a formal contract. And I’ve been travelling for two years so have zero income tax (only started working recently)
These are all documents they’ve asked additionally. We’ll see what they say.