bitcoind – What is the default username and password for bitcoin the rpc deamon?

What is the default username and default password for the bitcoin rpc?

I have a bitcoin daemon running, but there is no bitcoin.conf file. If I attempt to query the RPC, I get a 401 Unauthorized response

[root@host .bitcoin]# curl -i --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "getblockchaininfo", "params": [] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/
HTTP/1.1 401 Unauthorized
WWW-Authenticate: Basic realm="jsonrpc"
Date: Wed, 07 Sep 2021 01:23:45 GMT
Content-Length: 0
Content-Type: text/html; charset=ISO-8859-1

[root@host .bitcoin]# 

What is the username and password that bitcoin defaults to using?