Transform Request From GET With Queryparams to POST

Hi I want to sent request from GET with Queryparams to POST

GET => https://xxx.xxx/getNearestBirthdayAge?dtStartDate=1994-04-03

and i setting plugin transform request like this

  • http method = POST
  • add
    – header Content-Type:application/json

and my question how to set “dtStartDate” to body not on queryparams again ?