<…> my question is how much is required for each bitcoin account in one month, does the government free fees in each account

Fees are free for all Chivo to Chivo TXs, be it using BTC or USD. If non-Chivo wallets are involved in the TX, then regular network feed apply.

<…> I guess MasterCard and Visa cards would be used on this device except other card issuing companies would partner with El salvador

Currently, credit/debit cards don’t seem to be usable on the Chivo ATMs. Reading through their faqs (https://translate.google.com/translate?hl=en&sl=es&tl=en&u=https%3A%2F%2Fchivowallet.com%2Fpreguntas-frecuentes.html%23item-4&sandbox=1), the Chivo wallet can be charged only in cash if you’re using the ATM itself.