Asset Delivery Pack does not load on my device

I use fast-follow as asset delivery for my 20 videos of my application. I was inspired by the example “Google Play Asset Delivery in Android” (Google Play Asset Delivery in Android | by Jagdish Paryani | Mindful Engineering | Medium
and GitHub - Mindinventory/Google-Play-Asset-Delivery-Sample: How to use large amount of resources & assets in Android Apps?)

When launching the application on my iphone in debug mode, I should see that the fast-follow asset should be saved in my Samsung SM-A50 device, but it is not.

I’ve been looking for the reason why it won’t load for a week now without success. Could someone please help me?

Note: I only put one video for testing purposes (drAfrica)

The structure in Android Studio:

The structure on the disc

Basic manifest permissions

<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

fast-follow build.gradle

// In the asset pack’s build.gradle file:
apply plugin: ''

assetPack {
    packName = "fast_follow_asset_pack" // Directory name for the asset pack
    dynamicDelivery {
        deliveryType = "fast-follow"

app build.gradle
assetPacks = [":install_time_asset_pack",":fast_follow_asset_pack",":on_demand_asset_pack"]

settings.gradle = "myAppName"
include ':app'
include ':install_time_asset_pack'
include ':fast_follow_asset_pack'
include ':on_demand_asset_pack'

result after loading the app on Samsung A-50
The assets pack are missing in the “file” folder

Thank you again a thousand times for the time spent reading this cry for help and trying to correct me.