PHP 7.3 reaches end of support in December 2021 and Adobe Commerce 2.3.x reaches end of support in April 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.
Package
Use Composer to package your module.
- Using Composer to package a Magento 2 module
- Distribution on Commerce Marketplace only. Upload your package to the Commerce Marketplace