Sometimes, the issue might be with your Google Play Store itself. Try Restarting the Play Store or clearing its cache to see if that resolves the issue. You can also try updating the Play Store to the latest version.
If none of these solutions work, it's possible that the problem lies with your device's settings. Check your security settings to ensure that you're allowing app downloads from the Play Store. You might also need to enable the "Unknown sources" option, but be cautious when doing so.
Unlocking the Mystery: Why Can't I Download Apps on My Android?