Unc0ver tool released for iOS 12.4.8 version. Install Unc0ver latest version from below and Install Cydia.
Unc0ver iOS 12.4.8 Jailbreak support Devices
iPad Air 1
iPhone 6
iPhone 5S
Unc0ver iOS 12.4.8 Jailbreak Guide
Unc0ver Online ( Without PC ) IPA can be installed from Silzee.com online Jailbreak website and then follow below JB Guide to install Cydia.
Step 01. After installing Unc0ver Online IPA unlock your Device.
Step 02. Go to Settings > General > Profile and Device management > Trust the Unc0ver app.
Step 03. Open Unc0ver IPA from Home
Step 04. Tap the Jailbreak button to install Cydia.
Unc0ver Jailbreak PC + Online Guide ( AltStore )
Step 01. Open Unc0ver official site from Mobile Safari
Step 02. Download Unc0ver PC IPA
Step 03. Now install AltStore > According to your PC operating system ( Windows / Mac )
Step 04. Open AltStore from Mobile Device
Step 05. Go to My Apps > Tap + Button
Step 06. Now you can see Unc0ver IPA > Select it
Step 07. Waiting for Unc0ver IPA signing
Step 08. Open Unc0ver app from Home Screen
Step 09. Tap Jailbreak Button to install Cydia.
Unc0ver iOS 12.4.8 Jailbreak alternative
Checkra1n Jailbreak supports iOS 12.3 to iOS 14 Beta versions. But Checkra1n Jailbreak does not support for iOS 12.4.8 version. But still, Tweaked app stores support iOS 12.4.8 version. Download Tweaked app stores from below for iOS 12.4.8 version.
zJailbreak for iOS 12.4.8
zJailbreak semi jailbreak app store released initially for iOS 12 version and zJailbreak team update for iOS 12.4.8 version.
So zJailbreak iOS 12.4.8 users can install Cydia apps / Jailbreak apps / Tweaked apps / Cydia games from the zJailbreak app store.
You can install zJailbreak from the official web site. zJailbreak is an online Jailbreak solution. Open zJailbreak web site from Mobile Safari and install.