Upgradation of my Simple application - and integrating in app - app indexing in it.

I want to upgrade my simple application, integrating app indexing in it, so that if related content in my application is searched on Google, then my application should be suggested in Google search for downloading. I want in app indexing using Google firebase. Firebase app indexing includes deep linking in the application. My budget is bit low, Only bid if you can work in this budget, And know how to do in app indexing