Cannot enroll using apple developer app

Hi, thanks for reaching out! I will hand out this section of the Enrolling and Verifying Your Identity in the Apple Developer App - Support - Apple Developer article down below:  

Kind regards.

Enrolling in the Apple Developer Program as an individual

If you’re an individual or sole proprietor/single-person business, follow these steps to enroll in the Apple Developer Program through the Apple Developer app on iPhone, iPad, or Mac. Before you begin, you’ll need:

• An iPhone or iPad with Touch ID, Face ID, or a passcode enabled, or a Mac with the T2 Security Chip. You must use the same device for the entire enrollment process.
• An Apple ID with two-factor authentication turned on. Your Apple ID information must be valid and up to date — including, but not limited to, your first name (given name), last name (family name), address, phone number, trusted phone number, and trusted devices.
• The latest version of the Apple Developer app installed on your device.
• To sign in to iCloud on your device.

Start enrollment

1. Launch the Apple Developer app on the device you want to use for enrollment.
2. Tap or click the Account tab.
3. Sign in with your Apple ID. This can be different than the Apple ID signed in to your device, but must have two-factor authentication turned on.
4. If prompted, review the Apple Developer Agreement and tap or click Agree.
5. Tap or click Enroll Now.
6. Review the program benefits and requirements and tap or click Continue.

Enter your personal information

1. If requested, enter your first name, last name, and phone number. Your personal legal name will be listed as the seller on the App Store. Don't enter an alias, nickname, or company name as your first or last name, as entering your legal name incorrectly will cause a delay in the completion of your enrollment review.
2. You’ll be asked to verify your identity using your driver’s license or government-issued photo ID. Capture your photo ID and tap or click Confirm.2 For developers based in Mexico, driver’s licenses aren't accepted at this time.
3. Follow the steps on the next few screens:

• • Review your submitted information and tap or click Continue.
  • Select Individual as your entity type.
  • Review the terms of the Apple Developer Program License Agreement and tap or click Agree.

Complete purchase

Review your annual membership subscription details and tap or click the Subscribe button. Membership is provided on an annual basis as an auto-renewable subscription that renews until cancelled. You can make your purchase using one of your Apple ID payment methods.3 A receipt will be emailed to you, and you can resend the receipt to yourself via email at any time from Purchase History in Settings. You can cancel your subscription in Settings up to one day before your annual renewal date. Membership fees paid for the year during which you cancel are nonrefundable.

If your Apple ID is not supported, then you have to visit Before You Enroll - Apple Developer Program

Then scroll down and enroll. Hope this helps.