Google Play Store Search works differently compared to the Apple App Store. Depending on the name given to the App it is initially hard to see it in the search results.
Google has its own indexing rating logic for arranging apps in a Play Store search. App placement in search is influenced by a number of factors, such as the number of app downloads or whether the event name is unique.
At the time your Native App is published, you receive the direct link to the app at the Play Store from our support team. By using the provisioned link after the app creation process, you can easily announce the event by emailing it to attendees, linking or posting it to additional sites and social networks channel related to the event, or even generating a QR code to use in the advertising material before and during the event.
Consequently, the more people downloading the App from the link, the more sites pointing to the App link, the higher the App will appear in search results. That is, the better known the App is, the higher it will be listed in the Search Store search results.
If the time to promote the App before the event starts is too short, we recommend contacting Google Support to make use of other ways to better the position of the App at Google Play Store searches.
Here is also an article on Google Play help on the topic.
In the section: "I can't find my app with my app's search/position changed in search results." Some points about app visibility are listed in the Play Store search. These articles can help you talk better with Google Support.