The phrase references acquiring the installation file, in APK format, for a specific version of a popular sandbox video game on mobile devices, version 1.21. Such files are typically used to install applications on Android operating systems. An example would be a user searching for a way to obtain and install this particular game version on their smartphone or tablet.
Acquiring the software through this method may offer access to the game outside of official channels, potentially allowing users to bypass geographical restrictions or acquire the software without payment (though this is illegal and unethical). Historically, APK files have been a popular means for distributing Android applications, but this method also carries inherent security risks, as the files may be modified or contain malicious software.