Appointment Policia Federal: Request Code needed - where from?

Ola you lovely people :-)

I would love to get your insight on the following topic:

Background:
I married (uniao estavel) my partner in Rio de Janeiro. I will return to Rio to apply for permanent residency (Reuniao familiar) in January. I got almost all my documents together and translated and so on (woohooo).

Now I want to schedule the appointment at the Policia Federal to apply for the residency/Visa.

The big question:
How do I set up an appointment?

I found this page: LINK
Wonderful! But it says something about "Código de solicitação" - what is that? How do I get it?

Do I get it here? LINK And if so: It says that the date of entry has to be now or before that date, can't be in the future (January, when I return to Rio). So am I supposed to fill this out only when I enter Brazil? Which seems bad as friends tell me I have to schedule a meeting with Policia Federal really early...

Can someone help?

Muito obrigado, Valeu e Thank youuu!
Johannes

A Permanent Visa must be done in Brazil therefore some documents (Police Background, et al) cannot be xx days old before application. (Laws change in 2017 and do not want to give incorrect number of days.)
I have read many having issues as to getting DPF appointments. I am lucky as to our city is only 300,000 so able to walk into and normally get an appointment the next day or is not busy the ask me to wait..
I will "bump" to those who recently have done appointments.
Welcome and best of luck.