At the moment it is not possible to add agile boards to MyPage.

I would like to be able to add multiple Agile Boards to MyPage to use them to define workflows for the staff, easily accessible through MyPage.

This module already exists with a different vendor but I think it should be native RedmineUP.
https://www.redmine-x.com/redmine-agile-my-page-module#get-the-plugin