Error in preloading data in TextListQuestion using API

We are preparing a second round of a household survey . We need to preload the demographic data collected in the previous survey. We are using SuSo API to create the assignments by calling the end point /api/v1/assignments.

We are trying to preload the values of a TextListQuestion with the names of family members but we are getting the 400 code error “Invalida data”.

We are calling the endpoint in two different ways, using different json object:

Both calls get the same 400 error.

What is the correct way to preload values in a TextListQuestion using the API ?

Thank you

System expects one question to be provided.
Property name should be preserved as for any question: “Answer”
The expected value is a string containing an array of strings.
It might look like:

"Identity": "question_identity",
"Variable": "question_var",
"Answer": "[\"Mario\", \"Julia\"]"

Dear vitalii,
Thank you for your support, now it works ! (the escape character resolved the issue)