LabPlot 2.8.1 will be ready for the Microsoft store. As soon as https://binary-factory.kde.org/job/Labplot_Release_win64/ is building 2.8.1, we can publish it.
See T13860.
MS Store Submission guide: https://kate-editor.org/post/2019/2019-11-03-windows-store-submission-guide/
Discussion: https://www.reddit.com/r/kde/comments/dr01th/windows_store_submission_guide/
Submission: You may access the Partner Centre at https://partner.microsoft.com/en-us/dashboard
KDE @ MS Store: https://www.microsoft.com/en-us/search/shop/Apps?q=KDE+e.V.