my android app not uploading photo directly to Dropbox app folder using API

using logcat i got this system error

W/System.err: android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1513)
at java.net.Inet6AddressImpl.lookupHostByName(Inet6AddressImpl.java:117)
at java.net.Inet6AddressImpl.lookupAllHostAddr(Inet6AddressImpl.java:105)
at java.net.InetAddress.getAllByName(InetAddress.java:1154)
at com.android.okhttp.Dns$1.lookup(Dns.java:39)
at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:196)
at com.android.okhttp.internal.http.RouteSelector.nextProxy(RouteSelector.java:144)
at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:89)
at com.android.okhttp.internal.http.StreamAllocation.findConnection(StreamAllocation.java:190)
at com.android.okhttp.internal.http.StreamAllocation.findHealthyConnection(StreamAllocation.java:142)
at com.android.okhttp.internal.http.StreamAllocation.newStream(StreamAllocation.java:104)
at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:392)
at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:325)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:488)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:131)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:262)
at com.android.okhttp.internal.huc.DelegatingHttpsURLConnection.getOutputStream(DelegatingHttpsURLConnection.java:218)
at com.android.okhttp.internal.huc.HttpsURLConnectionImpl.getOutputStream(HttpsURLConnectionImpl.java:26)
at com.dropbox.core.http.StandardHttpRequestor.getOutputStream(StandardHttpRequestor.java:132)
at com.dropbox.core.http.StandardHttpRequestor.access$000(StandardHttpRequestor.java:29)
at com.dropbox.core.http.StandardHttpRequestor$Uploader.<init>(StandardHttpRequestor.java:141)
at com.dropbox.core.http.StandardHttpRequestor.startPostInStreamingMode(StandardHttpRequestor.java:81)
at com.dropbox.core.http.StandardHttpRequestor.startPostInStreamingMode(StandardHttpRequestor.java:29)
at com.dropbox.core.v2.DbxRawClientV2.uploadStyle(DbxRawClientV2.java:286)
at com.dropbox.core.v2.files.DbxUserFilesRequests.upload(DbxUserFilesRequests.java:3795)
at com.dropbox.core.v2.files.UploadBuilder.start(UploadBuilder.java:154)
at com.dropbox.core.v2.files.UploadBuilder.start(UploadBuilder.java:20)
at com.dropbox.core.v2.DbxUploadStyleBuilder.uploadAndFinish(DbxUploadStyleBuilder.java:92)
at com.example.decamera.MainActivity.uploadToDropbox(MainActivity.java:277)
at com.example.decamera.MainActivity.access$300(MainActivity.java:57)
at com.example.decamera.MainActivity$2.onImageSaved(MainActivity.java:173)
at androidx.camera.core.imagecapture.TakePictureRequest.lambda$onResult$1$androidx-camera-core-imagecapture-TakePictureRequest(TakePictureRequest.java:192)
at androidx.camera.core.imagecapture.TakePictureRequest$$ExternalSyntheticLambda0.run(Unknown Source:4)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7078)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:964)