How to make Supplier Contact Email for External Supplier Registration Page as non-editable

Summary:

We need to make supplier contact email address non-editable on the external supplier registration page to avoid any modification on email address.

At present on external supplier registration page, under contact section defaulted email address is still editable which we want to freeze for changes.

We tried VBCS approach as well to personalize this field but we option is not available as it is locked for personalization changes.

Please advise how we can make it non-editable for external supplier registration requests?
Adding Screenshot for better understanding of issue. Please refer attachments.

Thanks.

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