According to the Sitecore XM Cloud Documentation for Developers1, there are three ways to create an XM Cloud environment:

Using theSitecore CLI, which is a command-line tool that allows you to perform operations against local or remote XM Cloud instances.You can use the Sitecore CLI to create a project and an environment using thesitecore project createandsitecore environment createcommands2.

Using theXM Cloud Deploy app, which is a web application that allows you to create and manage projects, environments, and deployments.You can use the XM Cloud Deploy app to create a project and an environment using the user interface3.

Using theXM Cloud Deploy API, which is a RESTful API that allows you to programmatically interact with the XM Cloud Deploy app.You can use the XM Cloud Deploy API to create a project and an environment using HTTP requests4.

2:Walkthrough: Creating an XM Cloud project using the Sitecore CLI3:Create a project in the Deploy app4: [XM Cloud Deploy API Reference]1:XM Cloud Documentation for Developers - Sitecore