Crawl status saying it can't find any pages to index in my android app

Although I followed the below guide on my app (up to 7th step because I'm not interested in personal contents or on-device indexing):

Firebase appIndexing tutorial

And connected my app to firebase consol.

Also verified steps against "Get Started" guide:

Firebase AppIndex for Android Get Start guide

And followed steps included in Google guide to create deep link in app (except for reading data from coming intent section) as below link:

Google guide for creating deep link to app contents

I also verified the intent code in the manifest using adb command and got it successfully executed for specified url data (scheme, host, and pathPrefix) with added android:autoVerify="true".

The only thing I couldn't accomplish is to declare the "Digital Asset Links" file by uploading it to my website on Weebly, because I couldn't find a way through my search to do so.

Now, after I added the android app into my webmaster as a property and verified the ownership of my website on Weebly then associated the website to the app in the webmaster, I got the following message in the "Crawl status":

"We did not find any pages to index in your app Your app pages must be found and indexed before Google can start showing them in search results. You can tell Google which pages to index in a sitemap or in web page markup, or if your website and app have identical page organization, Google can infer your app pages from their corresponding web pages."

I'm really stuck here, and don't know what else to do to index my app contents keywords into Google Play for users to find my app when they search these keywords.

Is there any steps I missed in order to have my app indexed? or is there any other method to make my app on Google Play found when searching for specific keywords (that's all what I want, and I created the website specially for this task)?

Thanks in advance for your help.

App Indexing is for finding app pages in Google search, not in Google Play.

Unfortunately, you do need to associate the Digital Asset file, but this is just a text file in a known location: you can see the details in https://developer.android.com/training/app-links/verify-site-associations