To install PHP 8.5 on Debian 13, Follow the steps below.
Step 1 : Update the package list and upgrade existing packages.

Step 2 : Install the packages required to securely use external repositories.

Step 3 : Add the official SURY GPG key to verify PHP packages.

Step 4 : Add the SURY PHP repository to your system.

Step 5 : Update APT after adding the new repository.

Step 6 : Install PHP 8.5 and its core components.

Step 7 : Install popular PHP extensions required by most web applications.
- mysql: Enables MySQL/MariaDB database connectivity
- curl: Allows PHP to send HTTP requests to APIs and external services
- xsl: Transforms XML documents using XSLT
- gd: Provides basic image processing functions
- common: Contains common PHP files and dependencies
- xml: Enables XML parsing and manipulation
- zip: Allows creating and extracting ZIP archives
- soap: Supports SOAP-based web services
- bcmath: Provides arbitrary precision math functions
- mbstring: Handles multibyte character encoding (UTF-8 support)
- gettext: Enables translation and localization
- imagick: Advanced image processing using ImageMagick
Step 8 : Verify that PHP 8.5 is installed correctly.

You should see output showing PHP 8.5.x.
Congratulations! You have successfully installed PHP 8.5 on Debian 13.
