bitcoin core – How does `-rpcconnect` option work?

Its mentioned that -rpcconnect can be used to send commands to a remote Bitcoin Core node: https://github.com/bitcoin/bitcoin/blob/master/src/bitcoin-cli.cpp#L70

I am testing this option by using the format mentioned here: https://github.com/BlockchainCommons/Learning-Bitcoin-from-the-Command-Line/blob/master/14_1_Verifying_Your_Tor_Setup.md

torify bitcoin-cli -rpcconnect=vazr3k6bgnfafmdpcmbegoe5ju5kqyz4tk7hhntgaqscam2qupdtk2yd.onion -rpcport=1309 -rpcpassword=password3 getblockchaininfo

If I use the onion address for my node returned in getnetworkinfo, I get the below error:

error: Could not connect to the server vazr3k6bgnfafmdpcmbegoe5ju5kqyz4tk7hhntgaqscam2qupdtk2yd.onion:1309 (error code 1 - "EOF reached")

and If I use the onion address saved in /var/lib/tor/other_hidden_service/hostname, I get this error:

error: Authorization failed: Incorrect rpcuser or rpcpassword

I am assuming connection works fine in second error but issues with rpc credentials. Below are contents of bitcoin.conf:

testnet=1
prune=1000

server=1

listen=1
proxy=127.0.0.1:9050
torcontrol=127.0.0.1:9051
debug=tor

test.rpcport=18332

test.rpcuser=user3
test.rpcpassword=password3