To add an iCloud email to Gmail, you can follow these steps:
Go to the Gmail website and sign in to your account.
Click the gear icon in the top right corner of the page and select See all settings.
Click the Accounts and Import tab.
Under Check mail from other accounts, click Add an email account.
Enter your iCloud email address and click Next.
On the next page, select POP3 as the account type.
Enter the following settings:
POP Server: pop.mail.me.com
Port: 995
Username: Your iCloud email address
Password: Your app-specific password
Click Add Account.
Gmail will send a verification email to your iCloud account. Click the link in the email to verify your account.
Once you have verified your account, you will be able to send and receive emails from your iCloud account in Gmail.
To create an app-specific password for iCloud:
Go to your Apple ID account page.
Click Security in the sidebar.
Scroll down to App-Specific Passwords and click Generate New Password.
Enter a name for your password and click Create.
Your app-specific password will appear on the screen. Copy and paste it into the password field when setting up your iCloud account in Gmail.
Note: If you are using the Gmail app on your phone, you can also add your iCloud account by following these steps:
Open the Gmail app and tap your profile picture in the top right corner.
Tap Add another account.
If you see an option to add iCloud, select it. If not, tap Other.
Enter your iCloud email address and tap Next.
Enter your app-specific password and tap Next.
Follow the on-screen instructions to complete the setup process.
Once you have added your iCloud account to Gmail, you will be able to send and receive emails from both accounts in a single app.