I am trying to access my smb server running on my azure vm. I am uploading the file there from the android mobile app. Ignore the MainActivity.kt, I have shared a snippet of the code which is relevant to the issue.

BaseURL.kt

package com.example.qurantutor.network

object BaseURL {
    const val smbbaseUrl = "smb://$publicIP/shared/"
}

MainActivity.kt

private fun uploadRecitation() {
        val requestFile = RequestBody.create(MediaType.parse("audio/x-wav"), file)
        val body = MultipartBody.Part.createFormData("file", file.name, requestFile)
        val call = smbService.uploadFile(body)
        call.enqueue(object : Callback<ResponseBody> {

            override fun onFailure(call: retrofit2.Call<ResponseBody>, t: Throwable) {
                Toast.makeText(this@RecitationActivity, "Upload Failed With The Throwable: $t", Toast.LENGTH_LONG).show()
            }

            override fun onResponse(
                call: retrofit2.Call<ResponseBody>,
                response: retrofit2.Response<ResponseBody>
            ) {
                if (response.isSuccessful) {
                    // the upload was successful
                    Toast.makeText(this@RecitationActivity, "Upload Was A Successful", Toast.LENGTH_LONG).show()
                } else {
                    // the upload was not successful
                    Toast.makeText(this@RecitationActivity, "Error uploading file", Toast.LENGTH_SHORT).show()
                }
            }

        })
    }

RetrofitBuilderSmb.kt

package com.example.qurantutor.network

import io.github.cdimascio.dotenv.dotenv
import okhttp3.Credentials
import okhttp3.OkHttpClient
import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory

object RetrofitBuilderSmb {
    private val service: Retrofit = Retrofit.Builder()
        .baseUrl(BaseURL.smbbaseUrl)
        .client(getSmbClient())
        .addConverterFactory(GsonConverterFactory.create())
        .build()
    val smbService: SmbService = service.create(SmbService::class.java)

    private fun getSmbClient(): OkHttpClient {
        val dotenv = dotenv {
            directory = "/assets"
            filename = "env"
        }
        return OkHttpClient.Builder()
            .authenticator { _, response ->
                val username = "quranai"
                val password = dotenv["passwd"]
                response.request().newBuilder()
                    .header("Authorization", Credentials.basic(username, password))
                    .build()
            }
            .build()
    }
}

SmbService.kt

package com.example.qurantutor.network

import okhttp3.MultipartBody
import okhttp3.ResponseBody
import retrofit2.Call
import retrofit2.http.Multipart
import retrofit2.http.POST
import retrofit2.http.Part


interface SmbService {
    @Multipart
    @POST("/upload")
    fun uploadFile(@Part file: MultipartBody.Part): Call<ResponseBody>
}