CLN configuration help using bitcoin RPC password and username

Running CLN with the plugin from the latest PeerSwap commit using RPC password and username.
The plugin exits right after starting. What the problem could be?

logs:
```
INFO plugin-bcli: bitcoin-cli initialized and connected to bitcoind.
INFO lightningd: --------------------------------------------------
INFO lightningd: Server started with public key 03b2b374a259d2ec8ca46f7db079fbb12b6e307dbb319b1d2f911500e332e41d41, alias BIZARREARK (color #03b2b3) and lightningd v0.11.2
INFO plugin-peerswap-plugin: PeerSwap Initialized, running PeerSwap commit baf6e4c38d16dcd922f94e777bcd892db5b0bc5f
INFO plugin-peerswap-plugin: Liquid swaps disabled
DEBUG plugin-peerswap-plugin: connecting with RPC_USER, RPC_PASSWORD to :0
INFO plugin-peerswap-plugin: Killing plugin: exited during normal operation
```

config:
```
# lightningd configuration for bitcoin testnet
network=testnet
log-file=cl.log
log-level=debug:plugin-peerswap-plugin
plugin-dir=/home/bitcoin/tcl-plugins-enabled

# Tor settings
proxy=127.0.0.1:9050
bind-addr=127.0.0.1:19736
addr=statictor:127.0.0.1:9051/torport=19736
always-use-proxy=true

peerswap-bitcoin-rpcuser=RPC_USER
peerswap-bitcoin-rpcpassword=RPC_PASSWORD
peerswap-elementsd-enabled=false
peerswap-bitcoin-rpchost=localhost
peerswap-bitcoin-rpcport=18332
```