Install and switch to PHP 8.3 in WSL 2

Follow the steps below to install and switch to PHP 8.3 in WSL 2.

Step 1 - Update your package list

Run sudo apt update.

Step 2 - Install PHP 8.3

Run sudo apt install php8.3. This will install PHP 8.3 alongside PHP 8.2.
You can still use PHP 8.2 if you need it for certain projects.

Step 3 - Update your alternatives

Run the following commands to let WSL 2 use PHP 8.3 as default.

sudo update-alternatives --set php /usr/bin/php8.3
sudo update-alternatives --set phpize /usr/bin/phpize8.3
sudo update-alternatives --set php-config /usr/bin/php-config8.3

Step 4 - Verify the installation (PHP)

Run php -v to verify that PHP 8.3 is now being used.

Step 5 - Install additional extensions (optional)

You need to manually install extensions that you use for the new version.
This can be done by running the following command.

sudo apt install php8.3-cli php8.3-bcmath php8.3-curl php8.3-mbstring php8.3-mysql php8.3-tokenizer php8.3-xml php8.3-zip php8.3-fpm php8.3-redis

Not all are required, please check and see which extensions you need.

Step 6 - Verify the installation of extensions (optional)

Run php -m to get the list of all the compiled and loaded PHP modules/extensions. Check if the extensions that you have installed during step 5 are shown in this list.

Fixing issues

After installing PHP 8.3, I noticed that there was a problem with port 80.
It turned out that Apache was assigned to it automatically (instead of nginx), causing issues for Laravel Valet.

You might be interested in this article if you also encounter a port-related issue.