Node-Red Service-Call to Update Input Text Helper

I am using a service call to update an input_text value in HomeAssistant.

The service call works perfectly if I use {"value":"test message"} in the data field.

What I want to do is use the msg.payload however if I use {"value":msg.payload} I get the follow error.
"Call-service API error. Error Message: extra keys not allowed @ data['0']"
encasing the msg.payload in {} does not help and encasing the msg.payload in "" results in the input_text being updated with "msg.payload" and not the content of the payload.

For completeness the payload is a 36 character string coming from a function node.

Screen shot below:

Thanks in advance

I don’t know if this should work but I always did it with msg.payload.data going into the node.

EDIT:
This is the right way:

{"value":"{{payload}}"}

You can use mustache templating:
https://zachowj.github.io/node-red-contrib-home-assistant-websocket/guide/mustache-templates.html

That doesn’t work. The "{{payload}}" is treated as a string.
See below.

you have to turn off the “Use alternative template tags for the Data field” checkbox

Perfect! Thanks heaps this was drive me nuts. Learned something valuable.