Wiki: Required Documents for Portugal Golden Visa Renewal

You have two options essentially:

  1. register yourself for self-employment, obtain your own NISS, register online for Social Security portal, then obtain your no-debt declaration any time online (and of course you remember to de-register yourself from self-employment once you stop that activity)
  2. you get a confirmation that you are not registered with Social Security. For this you’d need a lawyer with the PoA, or you can go in person to a Social Security office, for which you may need to pre-book an appointment depending on which office you choose to visit.