Go to your Android Settings > Security (or Apps > Special app access ) and toggle on "Install unknown apps" for your mobile browser.

Upon installation, be wary of apps that ask for unnecessary permissions, such as access to your contacts, SMS, or camera, if the app’s function doesn't require them. How to Install the APK If you choose to proceed with the installation:

A popular third-party file-sharing site used by independent developers to host large files for free. Is It Safe to Download?

When dealing with APKs from third-party sources like Pixeldrain, you must exercise caution. Standard security practices include:

Sideloading apps can expose your device to security risks. Always maintain an active antivirus program on your device to block potentially risky sites and files. I want more fonts. - Microsoft Q&A

Since this app is not on an official store, it will not update automatically. You will need to return to the source (e.g., Hotzone18) to find newer "release" versions.

To understand what you are downloading, it is important to break down the query:

This is the originating domain, which typically hosts or promotes adult-themed mobile games and "visual novels."