Yes, use the Azure Functions Core Tools —
Usage: func azure functionapp <action> [-/--options]
fetch-app-settings Retrieve App Settings from your Azure-hosted
Function App and store locally Aliases:
fetch-app-settings, fetch
and
Usage: func azure functionapp <action> [-/--options]
publish Publish the current directory contents to an
Azure Function App. Locally deleted files
are not removed from destination.
<FunctionAppName> Function App name
--publish-local-settings [-i] Updates App Settings for the
function app in Azure during deployment.
--publish-settings-only [-o] Only publish settings and skip the
content. Default is prompt.
--overwrite-settings [-y] Only to be used in conjunction with -i or -o.
Overwrites AppSettings in Azure with local
value if different. Default is prompt.
There's also encryption for the local file if you feel a little adventurous —
run func settings
to get usage.