This page explains how you can publish your KDE app in the Microsoft Store.
Reserving a Name and Age Rating Your App
The first step requires some manual work. In Microsoft Partner Center you need to create a new app by reserving a name and then complete a first submission. How to do this has been described by Christoph Cullmann in the Windows Store Submission Guide. Don't hesitate to reserve the name of your app even if you are not yet ready for the first submission to the Microsoft Store. Once a name is reserved nobody else can publish an app with this name. Ask the KDE sysadmins for an account, if you need access to the Partner Center.
The first submission needs to be done manually because you will have to answer the age ratings questionnaire. On the first submission of your app you may want to restrict the visibility to Private audience until everything is ready for public consumption. You can create a customer group Foo Beta Testers with the email address of a regular Microsoft Store account in Microsoft Partner Center and then selected this group under Private audience. This way you can test installing your app with the Microsoft Store app before anybody else can see it.
Don't spend too much time filling out things like Description, Screenshots, etc. under Store Listings because some of this information will be added automatically from the AppStream data of your app for all available translations.
Semi-automatic App Submissions
The next submissions of your app can be done semi-automatically via the Microsoft Submission API with the submit-to-microsoft-store.py script.
The idea is that the script is run by a (manual) CI job as part of a full CI/CD pipeline. The app's release managers can trigger the job if they want to publish a new version on the Microsoft Store.
To run the script locally you need the credentials for an Azure AD application associated with KDE's Partner Center account. Anything else you need to know is documented in the script's README.md.
Making Your App Publically Available
The last step of the process to get your app published in the Microsoft Store is another manual submission which just changes the visibility to Public audience. This could also be done via the Microsoft Submission API (but not with the current version of the script), but it's probably a good idea to have a last look at the information about the app before it is published. In particular, you may have to fill out the Notes for certification, e.g. if your app cannot be tested without a service or social media account. For NeoChat we had to provide a test account for Matrix.
Moreover, you may want to fill out some details that are currently not available in the AppStream data, e.g. a list of Product features, the Copyright and trademark info, or special screenshots of the Windows version of your app.