How to Jailbreak 12.1.2 without computer. You can do it on iPhone or iPad.
How to Jailbreak 12.1.2 without computer using Unc0ver jailbreak tool. This Jailbreak 12.1.2 post is for informational purposes only. You make all manipulations with jailbreaking of devices at your own peril and risk. Be sure to backup your device using iCloud or iTunes before proceeding to jailbreak 12.1.2.
Step 1: To get make iOS 12.1.2 Jailbreak, go to next.tweakboxapp.com and tap Apps at the top of the screen.
--- all jailbreak ios 12.1.2 supported devices : list
Step 2: Tap Tweakbox Apps.
Step 3: Scroll down to find the unc0ver jailbreak iOS 12.1.2 version.
Step 4: Tab "Install" button and then confirm the popup box.
Step 5: Once the download unc0ver jailbreak iOS 12.1.2 completes, go on your iPhone to the Settings, then navigate to General > Profiles & Device Management > Select Trust from the confirmation box that pops up.
Step 6: After that tab on new unc0ver app on your Home screen and go to Jailbreak iOS 12.1.2. Wait...
Step 7: Now you can see Cydia iOS 12. Done.