Designing the addition of a phone number field to the Tilda user profile

It is necessary to design an extension of the Tilda user profile editing form, including a field for entering a phone number. The current version of the form includes fields: name and email.

The work is divided into three stages:

1. Designing the user interface (creating screen layouts necessary for implementing the function).
2. Designing API methods (defining requests and responses needed to save and retrieve the phone number).
3. Designing the database structure (developing tables and fields where the phone number will be stored).

All code blocks, if they appear, should remain unchanged; possible variables can be renamed for better readability.