Those days are long gone, I’m afraid. It’s not as simple as patching an IPSW like it used to be. The jailbreak scene has been pushed to the edge of a cliff by Apple with each update, especially after iOS 10. iPhone 8/8+/X and lower are jailbreakable for life due to an unpatchable bootrom exploit (checkm8), but it doesn’t mean much now that those devices won’t get iOS 17. Recently, Apple added another security measure (cryptex1) to make it near impossible to downgrade. It’s pure luck these days if/when a jailbreak gets released & for what iOS version. Oh and it’s been so long since the last untethered jailbreak, I can’t remember the name of the last one. All of them are Semi-Untethered (sideload an app with the exploit, but you would have to resign it every 7 days in case your phone reboots unless you own an Apple Dev Account)
Not as easy as it once was. Security was beefed up with every iteration after iOS 10, in the hardware (post-iPhone X) and the software. 10 was the last good time of jailbreaking ease, where a jailbreak.me type of exploit was released. It’s pure luck now. Most talented developers have either left the scene due to ungrateful people, sadly, or joined Apple’s Bounty program. You can’t tell what version a brand-new boxed iPhone is on because Apple obfuscated the serial numbers. iOS 15 introduced SSV (Sealed System Volume) meaning no touching root, forcing a halt which was eventually solved with “rootless” jailbreaks. They made it harder to downgrade to a jailbreakable version due to SEP (Secure Enclave Processor), and Blobs are useless now because of cryptex1, introduced in iOS 16. This means no downgrades to unsigned firmwares at all except within patch versions (like 16.3 and 16.3.1). iOS 17 could be even worse, time will tell.