State registration and other tax related information

I live in a place where there’s no landlines (phone and internet) and mobile reception is weak, so I’ve been spending quite a lot of money for mobile-based internet that is slow especially if the weather is bad. Hence I’ve decided to give Starlink a try…I don’t like E. Musk and didn’t want to, but there’s really no good alternative.

A couple of days ago I have ordered the hardware and I have opened an account, and the billing section is asking for information that I either don’t have or don’t know where to find. Here are the things it is asking me to fill in:

1) CPF (obv. no questions here)

2) State Registration (Inscrição Estadual - IE)

Enter your Inscrição Estadual (IE). Use 'ISENTO' (case-insensitive) if exempt. Format varies by state (2-15 digits).

I do not know if I have this number. I have entered ISENTO which it seemed to accept, but the application keeps asking me to update my information, so I’m thinking they need me to give a number.

3) Tax Regime (Regime Tributário)

Select your tax regime to determine CST/CFOP on invoices (NF-e, NFCom, NFS-e). Normal: Lucro Presumido or Lucro Real. Simples Nacional. MEI (Microempreendedor Individual)

Here I selected ‘Normal’ from the pop-up list, I think that’s the right one

4) Municipal Registration (Inscrição Municipal - IM)

Enter your Inscrição Municipal (IM) for ISS taxes on NFCom (mixed services) or municipal NFS-e. Use 'ISENTO' if exempt or not applicable. Format varies by city (check with prefeitura).

Again, no idea where to find this information. I entered ISENTO too, but I’m not sure why it keeps asking me to update my information, because of this or 2)

I am the holder of a temporary visa, a retirement visa, if that matters in this context