bitMapToFile ERR: java.io.FileNotFoundException:/storage/emulated/0/image.jpg: open failed:EPERM (Operation not permitted) in android

class ImageProcess {
    companion object {
        fun bitmapToFile(imageBitmap: Bitmap , filename: String): File? {
            val sd = Environment.getExternalStorageDirectory()
            val dest = File(sd, filename)
            try {
                val out = FileOutputStream(dest) //problem
                imageBitmap.compress(Bitmap.CompressFormat.PNG, 100, out)
                out.flush()
                out.close()
            } catch (e: Exception) {
                e.printStackTrace()
            return dest
this ERR!
W/System.err: java.io.FileNotFoundException: /storage/emulated/0/image.jpg: open failed: EPERM (Operation not permitted)
        at libcore.io.IoBridge.open(IoBridge.java:492)
W/System.err:     at java.io.FileOutputStream.<init>(FileOutputStream.java:236)
但我有android:requestLegacyExternalStorage="true"。
在文件AndroidManifest.xml中
<application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:requestLegacyExternalStorage="true"