Azure App Services
A feature of Azure App Service used to create and deploy scalable, mission-critical web apps.
This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
Normally the option is located under the Hosting Details section.
The currently supported versions of PHP (8.0/8.1) on Azure App Service are only supported on Linux. WordPress depends on PHP, so you can see why creating a new WordPress on App Service wouldn't offer a choice between windows/linux.
If the above was helpful please click Accept Answer.