rpc error: code = Unknown desc = dial tcp 103.102.44.207:9735: connect: connection refused
You need to connect to a node which has:


RPC enabled
username and password are known
client IPs are whitelisted using rpcallowip
the router has its port forwarding enabled.


Usually, public nodes don't share their RPC parameters, because that'd be very insecure. My advice is, run your own node. Otherwise, you could use the experimental neutrino client.