Android/Java: How to open gallery photo in webview android from html ? "<input type="file" id="file" name="picture" multiple="">"? doesn't work

Question

I created a button in html with the command

<input type="file" id="file" name="picture" multiple="">

that allows me to choose a photo in the gallery or to take a picture with the phone, but when I launch it from the webview, it doesn't work.

I did the same thing in my iOS version, and it works like a charm. It is a problem of permission ?

Here is my permission:

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WAKE_LOCK" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.WRITE_SETTINGS" tools:ignore="ProtectedPermissions" />
    <uses-permission android:name="android.permission.MANAGE_DOCUMENTS" tools:ignore="ProtectedPermissions" />
    <uses-feature android:name="android.hardware.camera" android:required="false" />

For info, if I launch it directly in the browser in the Chrome App, it works like a charm, I obtain the pop up I want :

I just need to find the way to make it work the same way in my app

Thanks