The x item must be a number so it should look like this:
{"x":1703953800000,"y":9}
Not knowing what the input data to your function node looks like makes it difficult to determine what your issue is. If the info I provided doesn't help, add a debug to the output of the influxdb-in node and copy and paste the output to a response.
There’s a great page in the docs (Working with messages : Node-RED) that will explain how to use the debug panel to find the right path to any data item.
Pay particular attention to the part about the buttons that appear under your mouse pointer when you over hover a debug message property in the sidebar.
In order to make code readable and usable it is necessary to surround your code with three backticks (also known as a left quote or backquote ```)
```
code goes here
```
You can edit and correct your post by clicking the pencil 
icon.
See this post for more details - How to share code or flow json
