Cannot install ActivityWatch on Ubuntu

I have downloaded the zip file, extracted it and added the aw-qt file to the startup applications. When I restarted, AW doesn’t show up on the top panel.
I cannot seem to open Activity Watch either. I get the following error when I try to run ./aw-qt

Address already in use
Port 5600 is in use by another program. Either identify and stop that program, or start the server with a different port.

localhost 5600 doesn’t work either.
Can someone please help me out? I really want to get this up and running…

When you say “localhost 5600 doesn’t work” can you elaborate?

What do you see when you visit http://localhost:5600 in your browser?

And what does lsof -i :5600 show? That should give you a clue to what is using port 5600.