I am trying to redirect a call from a number torward another and I don’t know how to send the *21*telNum# with the android api

Here is my latest attempt:

import android.Manifest
import android.content.Intent
import android.content.pm.PackageManager
import android.net.Uri
import android.os.Bundle
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.ActivityCompat
import androidx.core.net.toUri
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import org.linphone.LinphoneApplication.Companion.corePreferences
import org.linphone.R

class ConfirmRedirectionActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_confirm_redirection)
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }
        findViewById<android.widget.Button>(R.id.button).setOnClickListener { setupForwarding() }
    }

    fun setupForwarding() {
        if (ActivityCompat.checkSelfPermission(
                this,
                Manifest.permission.CALL_PHONE
            ) != PackageManager.PERMISSION_GRANTED
        ) {
            ActivityCompat.requestPermissions(
                this,
                arrayOf(Manifest.permission.CALL_PHONE),
                CALL_PHONE_PERMISSION_REQUEST_CODE
            )
            return
        }


        fun telCall(telNum: String) =
            startActivity(
                Intent(Intent.ACTION_CALL).apply {
                    flags = Intent.FLAG_ACTIVITY_NEW_TASK
                    data = Uri.fromParts("tel", telNum, null)
                    Log.i("About to call $data")
                }
            )
        telCall("##002#")
        Log.i("Cleared call forwarding")
        telCall("*21*${intent.getStringExtra("telIn") ?: ""}#")
        Log.i("Call forwarding enabled")

        corePreferences.firstStart = false
        startActivity(Intent(this, MainActivity::class.java)) // Go to dialer view
        finish()
    }

    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<out String>,
        grantResults: IntArray
    ) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        if (requestCode == CALL_PHONE_PERMISSION_REQUEST_CODE) {
            if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                setupForwarding()
            } else {
                // TODO: Handle permission denied
            }
        }
    }

    companion object {
        private const val CALL_PHONE_PERMISSION_REQUEST_CODE = 100
    }
}

And that doesn’t show any reaction from the app it just redirects it torward MainActivity (as expected) without having the redirect set up as checked by “calling” *#21#

I’ve also tried using TelecomService.placeCall (it only makes a call, it doesn’t do the mmi code) and TelecomService.handleMmi ( it requires that you are the system dial app, which I am not)