build.sbt

val scala3Version = "3.1.0"
val http4sVersion = "1.0.0-M34"
val circeVersion = "0.15.0-M1"

lazy val root = project
  .in(file("."))
  .settings(
    name := "social n' stuff",
    version := "0.1.0-SNAPSHOT",
    scalaVersion := scala3Version,
    libraryDependencies ++= Seq(
      "com.novocode"   % "junit-interface"     % "0.11"        % "test",
      "org.typelevel" %% "cats-core"           % "2.7.0",
      "org.typelevel" %% "cats-effect"         % "3.3.4",
      "org.http4s"    %% "http4s-ember-client" % http4sVersion,
      "org.http4s"    %% "http4s-circe"        % http4sVersion,
      "org.http4s"    %% "http4s-dsl"          % http4sVersion
    )
  )

Hello.scala

package gov.dhs.dsa

import cats.effect.{IO, IOApp, ExitCode}
import cats.implicits._
import org.http4s._
import org.http4s.implicits._
import org.http4s.ember.client._
import org.http4s.client.dsl.io._
import org.http4s.Method._

object Hello extends IOApp {
  override def run(args: List[String]) = for {
    test <- EmberClientBuilder.default[IO].build.use { client =>
      client.expect[String](POST(UrlForm(
        "client_key" -> clientKey,
        "client_secret" -> clientSecret,
        "access_token" -> accessToken
      ),
      uri""))
    }
    _ <- IO { println(test) }
  } yield ExitCode.Success
}