After a lot of swearing and trying things I have finally managed to succesfully install go, MQTT and find (server) on the raspberry pi 3. I can also succesfully send the command to make a group (curl -X PUT "192.168.19.103:8003/mqtt?group=groupnanne". I get the response that the group has been created, I get the password for the group and if I try to make the exact same group again it tells me your password exists and it relists the password.

However, I cannot access the group from my phone, other raspberry pi (with ARM client), from my laptop or indeed even login to the group on the browser at 192.168.19.103:8003. The phone gives an error: undefined, the windows client also spews out errors and my arm client on raspi keeps sending the fingerprint to the ml.internalposition.com , as changing the URL apparently is not possible on ARM?