How to add debit card

It is really confusing when you ask two unrelated questions.

This document explains how to add a payment method to your Apple ID on a Mac, Apple mobile devices, PC, or online. Click here --> Add a payment method to your Apple ID - Apple Support

On an iPhone:

Open the Settings app.

Tap your name.

Tap Media & Purchases, then tap View Account. You might be asked to sign in with your Apple ID.

Tap Manage Payments.

Changing Apple IDs is unrelated to SIM cards. It also depends upon what you mean by "change".

Here's how you change the email address you use for your Apple ID:

1. Go to https://appleid.apple.com and sign in.

2. In the Sign-In and Security section, choose Apple ID.

3. Enter the email address that you want to use as your Apple ID.

4. Choose Change Apple ID.

5. If you changed your Apple ID to a third-party email address, check your email for a verification code, then enter the code. Learn what to do if you didn't get the email. --> If you didn't receive your verification or reset email - Apple Support

6. If you use services like iCloud or Messages to share with friends and colleagues, sign in to those services with your updated Apple ID. --> What to do after you change your Apple ID or password - Apple Support

For more details, read the document: "Change your Apple ID" --> Change your Apple ID - Apple Support

Or do you mean this by "change"? -->

Read this support article to learn how to sign in with your Apple ID on different devices--> Sign in with your Apple ID - Apple Support

For an Apple Mobile device:

1. Open the Settings app.

2. Tap Sign in to your [device].

3. Enter your Apple ID and password.

4. If prompted, enter the six-digit verification code sent to your trusted device or phone number and complete sign in.

If another Apple ID is signed in you may need to enter the password for that ID to sign out of that ID first.

Your post is confusing.

Your tile is one question, and your actual body is a different question entirely.

What exactly do you wish to know?

To add a debit card, tap the icon at the top right corner of the Wallet App.

click here ➡️ Set up Apple Pay - Apple Support

If you just get the Lear More dialog, make sure your iPhone is set to a country where Apple Pay is supported in Settings ➜ General ➜ Language & Region ➜ Region

click here ➡️ Countries and regions that support Apple Pay - Apple Support

Your Apple ID and SIM card have nothing to do with each other. Inserting a SIM card does not in any way limit the ability to change Apple IDs.