How to pass raw-data into post request using HTTParty

I have to make this request in rails 6:

curl --location --request POST 'https://api.web2sms237.com/sms/send' \
--header 'Content-Type: application/json' \
--data-raw '{
	"sender_id": "MyApp",
	"phone":"+237699112233",
	"text":"Web2Sms237 is an awewome app!",
	"flash":false
}'

We usually use HTTParty to make http requests, but i faced some problems trying to pass raw data into the request. I’ve already tried:

result = HTTParty.post(
        "https://api.web2sms237.com/sms/send",
        headers: {
          "Content-Type": "application/json",
        },
        body: {
          sender_id: App.first.name.upcase,
          phone: "+237#{@phone}",
          text: @message,
          flash: false
        })

And in all cases, the response says that no data was passed (all my dara are ok) how can i solve this issue

{"message":"The given data was invalid.","errors":{"phone":["The phone field is required."],"text":["The text field is required."]}}