How in my case to correctly configure tcppm between two machines?

Question

proxy

There is machine number 1, with internal IP - "192.168.56.4" and external unknown IP "ip1
"
machines so that the proxy 2.2.2.2:1515:user:pass gives the IP "ip1".
What have I done wrong?
Registered on machine number 1

auth iponly
allow * * 192.168.56.1
tcppm -i2.2.2.2 1515 192.168.56.4 3128
flush

Registered on machine number 2

users user:CL:pass
auth strong
allow user
proxy -i192.168.56.4
flush

Answer 1

allow * * 192.168.56.1 only allows access to IP 192.168.56.1 and you need access to 192.168.56.4.
For the future - in such cases, logging helps a lot.