The permission is denied because you didn't use
sudo. However, deleting the old certificates is probably not helpful.
For now, why don't you run
sudo certbot certificates to make sure of which certificates you have, and then try following Step 7 of the tutorial over again using your new certificate for
askmate.net.br instead of
Since Step 7 relies on having the variable
DOMAIN set in your shell, you would also need to do that from Step 3 (that is,
DOMAIN=askmate.net.br) before following Step 7.
If you replace the certificate this way, it's likely to at least work for
askmate.net.br, which could be a good first step.
(Assuming that works properly, my long-term suggestion would probably be to ask on the Bitnami forums whether anyone has a better tutorial applicable to your situation, because I think that, even though this tutorial is published by Amazon itself, it's not really following the way that Bitnami and the Bitnami community would expect you to do it! For example, we know from other threads here on the Let's Encrypt forum that Bitnami has its own guide for installing Let's Encrypt certificates on Bitnami, and that guide doesn't use Certbot at all!)