Clarity on creating for both Android and IOS?

I've just recently released my 2nd game for Android but want to get this one out for iOS as well.
I've always developed on Unity for Windows as I don't own a mac (but I have access to an iphone temporarily).

So I've come up against walls.. I managed to install vmware workstation and MacOS Monterey so I can install Xcode, feel like I'm getting somewhere.
The plan was to build in Unity, open the project in Xcode on the MacOS VM and build from there.
Except that doesn't work because it says Firebase cannot be built in Unity for an iOS build.. (I use Firebase for game saves and ghost data for each player's fastest laps, given It's a racing game).

So how best should I proceed here?
I'm potentially looking at running Unity on both Windows AND my MacOS VM, is that right?
I can't see Unity running very well inside a VM somehow, and I'd be contending with 2 copies of my project?
Any general advice here is appreciated, I'm really stuck as to what the best way to do this is.

 

I have never managed to get a macos vm to properly build and upload to testflight (it checks the hardware ID, which doesnt exist on a VM).
If you use version controll you can work on the project on multiple devices at once. Then you can just use build and run

 

Oh that's not good but thanks for letting me know.
The annoying thing is I could have access to an old mac, but it's 10 years old and won't run Monterey which means in turn I can't run Xcode as it now requires that. God I hate Apple..

I will look into version control as an aside, so far I've only taken manual backups, it's been on my rather large 'learn this' list!

I guess Apple make it difficult on purpose so only larger companies can generally create apps, they don't want average Joe solo developer like me on their app store..

 

Yeah I also have a big annoyance towards apple. To make apps for an iPhone you need an iPhone, mac and $100/yr license...