this is what i got when i typed "how to install
apk android" into my search bar


Enable Installation from Unknown Sources

Before installing any APK, you must allow installations 
from unknown sources:

Android 8.0 and above: Go to Settings > Apps & notifications >
 Advanced > Special app access > Install unknown apps, then
  select your browser or file manager and toggle Allow from this 
  source. 
Android 7.0 and below: Go to Settings > Security, then enable
 Unknown sources. 
Download the APK File
Obtain the APK from a trusted source such as APKMirror, APKPure,
 or the official developer’s website.  Avoid unverified sites to
  reduce malware risk.

Install the APK

Via browser: Download the APK file, then tap the notification or 
Open the file.  Tap Install when prompted.
Via file manager: Open your file manager (e.g., My Files on 
Samsung, Files by Google on stock Android), locate the APK in your
 Downloads or Internal Storage folder, tap it, and select Install. 
From a PC: Transfer the APK via USB (set connection mode to File 
Transfer), then install using your file manager as above.