In case you have a testing release that you want to release to public, you just have to promote the testing by following the steps below.
Promote Testing release to Production
Go to your Google Play Console.
On the left menu, select
Testingand click on testing phase that you want to promote.
Promote releasedropdown and select
You will be redirected to Production Release page, click
Review Releaseat the bottom of the page.
On the next page, you may see a Warning box. Click on the
View Warning Messageand a popup will appear. You can ignore the warning if it is about Unoptimized APK.
Lastly, at the bottom of the page, click
Start roll-out to Production. Your app will be reviewed and this usually takes a few days, but can occasionally take more before it gets published.