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.
Prepare (development quick start)
Before you start building Magento modules, we suggest you use the following checklist:
- Install Magento and any required dependencies
- Set Magento for developer mode
- Decide which type of component you’re creating and how to set it up in
composer.json. - Understand the component file structure