Let’s kill the myth immediately. There is no software that can permanently remove the iCloud lock from an iPhone 5s on iOS 12.5.7 permanently if you do not have the original credentials.
Any tool that claims to "unlock forever" or "IMEI remove" for a one-time fee on a 5s is either: iphone 5s ios 12.5.7 icloud bypass
The only legal, permanent removal is to contact Apple Support with the original proof of purchase. Let’s kill the myth immediately
Since the iPhone 5s uses the A7 chip, it is vulnerable to the checkm8 bootrom exploit. This is a permanent, unpatchable hardware vulnerability. However, checkm8 requires a computer and specialized software. Here is the current landscape for iOS 12.5.7. The only legal, permanent removal is to contact
Activation Lock is Apple’s anti-theft feature. It links the device to the owner’s Apple ID. Even if you restore the phone via iTunes (or Finder), you will be stuck on the "Hello" screen asking for the original email and password. Without these, the phone cannot be used as a standard cellular device.
SEO is filled with sites claiming "Official iPhone 5s iOS 12.5.7 iCloud Bypass Factory Unlock." Be skeptical.