The Location where iPhone saves your Notes depends on the Default Notes Account. You can find below the steps to change default Notes Account on iPhone.
Change Default Notes Account on iPhone
When you write a Note on iPhone, you can control where the Note will be saved by selecting a Default Account for the Notes App on your device.
If you select iCloud as the Default Account for Notes App, all Notes will be saved to iCloud and become available on your MacBook, iPad and other devices.
If you select “On My iPhone” as Default, your Notes will be stored locally on the internal storage of your iPhone and won’t appear on other devices.
You can Add Multiple Accounts to the Notes App, including third-party services like Gmail and select any one of them as the Default Account.
1. Set iCloud As Default Account for Notes App
If you want to see your Notes from iPhone appearing on MacBook and other devices, you need to set iCloud as the Default Account for Notes App.
Go to Settings > Notes > scroll down and tap on Default Account. On the next screen, select iCloud as the Default Account.
After this, all Notes that you write on iPhone will be automatically saved to your iCloud Account and they will be accessible on all your devices.
2. Save Notes Locally on iPhone
You can make Notes App to save all your Notes on the Local or Internal Storage of iPhone by selecting “On My iPhone” as the Default Account for Notes App.
As mentioned above, all your Notes will only be confined to iPhone and you won’t be able to access them on your MacBook or other devices.
Go to Settings > Notes > scroll down and tap on Default Account. On the next screen, select On My iPhone as the Default Account.
After this, all Notes that you write on iPhone will be automatically saved to the internal storage of your iPhone.