I think you can try this
 private void Verifypermissions()
{
    Log.d(TAG,"Verify permissions: asking user for permissions");
    String[] permissions={Manifest.permission.READ_EXTERNAL_STORAGE,
            Manifest.permission.WRITE_EXTERNAL_STORAGE,
            Manifest.permission.CAMERA};
    if(ContextCompat.checkSelfPermission(this.getApplicationContext(),
            permissions[0])== PackageManager.PERMISSION_GRANTED
            && ContextCompat.checkSelfPermission(this.getApplicationContext(),
            permissions[1])==PackageManager.PERMISSION_GRANTED
            && ContextCompat.checkSelfPermission(this.getApplicationContext(),
            permissions[2])==PackageManager.PERMISSION_GRANTED)
    {
        return;
    }
    else
    {
        ActivityCompat.requestPermissions(MainActivity.this,permissions,REQUEST_CODE);
    }
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    Verifypermissions();
}
you can include the required permissions inside the string array