NetworkSecurityConfig: No Network Security Config specified, using platform default Error response code: 400

Try these solutions

Solution 1)

Add the following attribute to the <application tag in AndroidManifest.xml:

android:usesCleartextTraffic="true"

Solution 2)

Add android:networkSecurityConfig="@xml/network_security_config" to the <application tag in app/src/main/AndroidManifest.xml:

<application
        android:name=".ApplicationClass"
        android:allowBackup="true"
        android:hardwareAccelerated="false"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:largeHeap="true"
        android:networkSecurityConfig="@xml/network_security_config"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

With a corresponding network_security_config.xml in app/src/main/res/xml/:

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="true" />
</network-security-config>

Refer this answer for more info: Download Manger not working in Android Pie 9.0 (Xiaomi mi A2)

Edited Answer Remove <domain includeSubdomains="true">secure.example.com</domain> from the code.

Use just:

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="true" />
</network-security-config>

And It will work for any URL or IP.

Try to set cleartextTrafficPermitted=false

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
       <domain includeSubdomains="true">secure.example.com</domain>
    </domain-config>
</network-security-config>