How do I secure Apple ID from unauthorized access?

I received this message on my phone:

[Apple Security Alert]

We have noticed unusual activity on your Apple ID (Case ID: 10215467944),

including a pending $449.98 transaction at the "APPLE STORE – Orlando,

FL" via Apple Pay Pre-Authorization. Additionally, there have been

multiple unauthorized sign-in attempts and Apple Pay activation requests from

unfamiliar locations. To protect your account, we've temporarily blocked these

actions and placed the transaction on hold as a precaution.

If

this was you, no further action is required, and the transaction will be

processed automatically within 24 hours. However, if you do not recognize this

activity, please contact Apple Support immediately at (888*******45.

For

assistance, you can reach us through the following support options:

Customer

Support: 1-*******5

Billing

Assistance:****

Your

prompt attention to this matter is appreciated.

Sincerely,

Apple

Support Team

[Edited by Moderator]