Swift : How I can try API call with POST having parameters and headers with URLSession?

Question

I found some pages but there were no clear contents.

1. I have to use POST type of call

2. There is 3 needed parameters below.

a) name = source, type = String

b) name = target, type = String

c) name = text, type = String

3. The code below is the expected response of API call.

4. These are the example of requests with headers

I hope I want to know how I can put this data into the body of a struct for data.

Thank you!