I got APK file from my developer saying that, that is all I need. I've been stuck in the part of signing the app. I have read through the articles and from what I understand I need a .ks file or private key to finish the procedure. I'm not sure if I understand the app signing process or should I download Android studio to sign the app manually.
If the developer has signed the app, what is my procedure henceforth? Would I need a keystore file?