Download iOS on Android devices?

I would like to buy an Android device soon (Huawei p20 (pro)). But since I miss iOS so much, I ask if you can download any iOS on Android devices (best of all, that it contains updates like the iPhone updates.

Simple answer: No!
Apple does not open source and makes its OS so easily available.

Buy either Apple device or no iOS

You can't get an iOS without a device from Apple.

Either you buy an iPhone or iPad and then have iOS or you buy a Huawei and waive iOS. There's no compromise.

IOS or OS X work with a boot loader, the so-called iBoot. For the system to be started, ie iOS certified, you need a trust bootloader that certifies the software.

So you need an iBoot, but that's not all.

Of course, Apple also makes a lot of open source, although iOS is partially closed source.