Safely copies current wallet file to destination, which can be a directory or a path with filename.
destinationstringREQUIREDcurl --user myuser --data-binary '{"jsonrpc":"1.0","id":"1","method":"backupwallet","params":["/tmp/backup.dat"]}' -H 'content-type:text/plain;' http://127.0.0.1:8332/null