Unable to carryout HTTP post on Android

For production, you should be using https.

For development, you can set the clearText to true in the capacitor.config - Reference.

If clearText doesn’t work for you, you can set the Network security configuration directly in your Android config.

AndroidManifest.xml

<application
  ...
  android:networkSecurityConfig="@xml/network_security_config"
  ...
>
...
</application>

res/xml/network_security_config.xml

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