make install will install libbrlapi.so in /lib, and include files in
/usr/include/brltty. An authorization key will also typically be set in
/etc/brlapi.key (if it is not, just create it and put arbitrary data in it), but
it won't be readable by anybody else than root. It is up
to you to define a group of users who will have the right to read it and hence
be able to connect to the server. For instance, you may want to do:
# addgroup brlapi
# chgrp brlapi /etc/brlapi.key
# chmod g+r /etc/brlapi.key
# addgroup user1 brlapi
# addgroup user2 brlapi
...