Contributions through pull requests are not supported for this topic. Open a GitHub issue to provide feedback.
PHP 7.3 reached end of support in December 2021 and Adobe Commerce 2.3.x reaches end of support in September 2022. You may want to consider planning your upgrade now to Adobe Commerce 2.4.x and PHP 7.4.x to help maintain PCI compliance.
The Magento_CustomerCustomAttributes module handles user-defined customer and customer address attributes.
User-defined attributes are the ones, which are created by a store administrator additionally to the default ones.