The backupwallet RPC safely copies `wallet.dat` to the specified file, which can be a directory or a path with filename.
backupwallet "destination"
*bitcoin-cli help backupwallet
backupwallet "destination" Safely copies current wallet file to destination, which can be a directory or a path with filename. Arguments: 1. "destination" (string) The destination directory or file Examples: > bitcoin-cli backupwallet "backup.dat" > curl --user myusername --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "backupwallet", "params": ["backup.dat"] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/