use appassets.androidplatform.net without ssl (for sending ajax requsets by http)

I`m working on webview android app, and I load my html and js code via "https://appassets.androidplatform.net/assets/www/index.html", but in my js code I use ajax requests to API which is running without ssl, so js doesnt allow me to make ajax requests from https origin to http server. When I try to use http://appassets.androidplatform.net/assets/www/index.html I get an error 'net::ERR_NAME_NOT_RESOLVED'. Is there any way to make it work without buying ssl for API server or using file:// protocol for loading code?

I dont know if it helps, but here is my code for WebViewAssetLoader:

assetLoader = new WebViewAssetLoader.Builder()
            .addPathHandler("/assets/", new WebViewAssetLoader.AssetsPathHandler(this))
            .addPathHandler("/res/", new WebViewAssetLoader.ResourcesPathHandler(this))
            .build();

and

public WebResourceResponse shouldInterceptRequest(WebView view,
                                                      WebResourceRequest request) {
        if (String.valueOf(request.getUrl()).endsWith(".js")) {
            try {
                return new WebResourceResponse("text/javascript", "UTF-8", getAssets().open(String.valueOf(request.getUrl()).replace("http://appassets.androidplatform.net/assets/","")));
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return assetLoader.shouldInterceptRequest(request.getUrl());
    }

The answer was quite simple
Firslty, I have to add android:usesCleartextTraffic="true" into <application> tag.
And secondly I have to use webView.getSettings().setMixedContentMode(WebSettings.MIXED_CONTENT_ALWAYS_ALLOW); in my activity.