Photos not sent through email node

Hello, beginner question, but my digging hasn't turned anything up so far (I've read three google groups about similar issues and one came very close to my problem--and it directed me to a Node-Red slack; Stack Overflow has been less than enlightening).

When I wire my camerapi to take photos on an interval using the nodes, the camera posts the appropriate images to the designated folder, but when I then direct the flow into an email node without a function I get a filename that isn't an image, and with a function I get a header and a placeholder "[native code]" text scrawl. Let me know if there's anything else I can provide to simplify things.

The javascript function node I put between the camerapi node and the email node has the following code:

msg = {
payload : "Test Photo Mail " + new Date().toString(),
topic : "Next Photo"
return msg;

I've found this and have attempted Bart's four flow solution:!topic/node-red/tvWErCxIFdA

But my research hasn't told me how to get the jsonata editor going like in those screenshots. The other posts on this forum have also used the same screenshots.

How do I get to this change > JSONata Expression Editor?

If you have an image in a node-red flow it will be as a binary buffer. To add it to an email you would need to encode the binary buffer using the base64 node and then move it so that it is in the correct part of the message (read the info panel for the email node)