Well, the premod is still phpBB. So the message tells you to put the generated .htaccess in your domain's root, eg, where eduardomoreira.com.br/ does actually leads in your ftp.

The generated .htaccess should mention the forum/ directory, it it does not, then you have something wrong in your server config : phpBB Server and Cookie settings

Then, since you where able to run the mod_rewrite test, you should have no trouble with the phpbb .htaccess, just make sure that you a) do not do an obvious mistake and b) that you use the same slashes as in your test.

And it will work

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