Custom Action Post with nested json list

I have an api endpoint used to create records and the body of the request has a nested list of names that I must pass during the post (“adult_names”)
Here is an example
“serviceid”: 12,
“service_name”: “VIP Assistance Service”,
“price_adults”: 0,
“price_children”: 0,
“price_pets”: 0,
“booking_price”: 0,
“booking_tax”: 0,
“booking_total”: 0,
“payment_method”: “credit card”,
“adult_names”: [
“Name”: “John Doe”
“Name”: “Peter Pan”
“customer_account”: “0000009244”,
“customer_tax_id”: “0999223001293”
can’t figure out how to do this part of the custom action, would appreciate any help