After rebooting, open the Play Store. It may ask you to sign into your Google account. If you were already signed in, it will refresh automatically. Give it up to two minutes to update its internal components.
Android 5.1.1 (Lollipop) was released in 2015. While it was revolutionary at the time, modern app development has moved to Android 8.0+ (API 26). You might have noticed that apps crash, the Play Store hangs on "Downloading," or you simply cannot find the latest versions of your favorite apps. Google Play Store Apk Download For Android 5.1 1 Extra
Since Android 5.1.1 is no longer officially updated by Google, you must use a trusted archive: After rebooting, open the Play Store