Hello @Deborah1586 , yes it is required by law. I can explain to you how I do it.
2 days before arrival my guests receive a scheduled message with a Registration form (I use a Google Form where guests can write answers to all questions).
After registration I fill out the "Boletim de alojamento" on the SIBA website. It is not dufficult at all. Let me know please if you have any questions.
Kind regards.
Elena.