macOS without iCloud or with passwords

Call Customer Support (800) MY–APPLE (800–692–7753)

Outside the USA—Contact Apple for support and service by phone

See a list of Apple phone numbers around the world.

Contact Apple Support - Apple Support

Local USA—

Store List - Apple Store - Apple

Around the World—

Choose your country or region - Apple

You can access your iCloud data at iCloud.com

You could create a new Apple Account to use with Xcode, and access your other account via the web.

bediicco wrote:

Why do you think i should call them? Every question can be asked there but this is a little bit too much i think

that's correct: " this is a little bit too much ..."

Apple gets paid to entertain such questions.

I would suggest to create a separate local account for Xcode and iCloud Sign-in on Demand:

A. Create a Local User Account for Development

Go to System Settings > Users & Groups and create a user account (Standard). For example "XcodeDev"

Set this account to log in automatically without a password. Go to System Settings > Users & Groups > Login Options and set "Automatic login" to the "XcodeDev" account.

Disable FileVault for this setup if you don't want encryption: System Settings > Privacy & Security > FileVault > Turn Off.

B. Install Xcode on the Local Account

Download and install Xcode from the App Store or Apple's developer site under "XcodeDev" account. iCloud is not needed for this.

C. Sign in to iCloud Manually when needed

Don't sign into iCloud during the initial setup of this account

When you need iCloud data, go to System Settings > Apple ID and sign in with your Apple ID. It will prompt you for the password and the 2FA code from your second device.

After signing in, you can access iCloud services as needed. (Keychain, Photos, etc.)

Sign out of iCloud when you're done (System Settings > Apple ID > Sign out)

D. Sidecar Display Setup

For Sidecar, you'll need to sign into iCloud at least once to pair your iPad (it will require an Apple ID). After pairing, Sidecar should work without constant iCloud access as long as both devices are on the same Wifi Network.