Xmrig, solo-mine to node on another machine

Hello,

I'm trying to follow the instructions on https://docs.getmonero.org/interacting/mining/guides/solo/xmrig-solo/

But the instructions seem to assume that the node is on the same machine as xmrig, whereas I'm trying to point the hashpower from the machine with xmrig to another of my machines with the monero node.

Lets call the machine with the node "Machine A" and the machine with Xmrig "Machine B".

Here is the command I'm using to start my node on Machine A: ./monerod –out-peers 32 –in-peers 64 –add-priority-node=p2pmd.xmrvsbeast.com:18080 –add-priority-node=nodes.hashvault.pro:18080 –disable-dns-checkpoints –enable-dns-blocklist

And here is my command to start Xmrig (prepared for me by the wizard on xmrig.com) on Machine B: ./xmrig –donate-level 5 -o 0.0.0.0:18081 -u MY-ADRESS –coin monero –daemon

When I run these, I get the error in Xmrig: connect error: "connection timed out"

Does anybody know what could be wrong?

thank you,