How to show polygon data in Power BI

Editor → Current Situation (Ribbon tab) → Administrative (Ribbon bar) → Show Neighborhoods (Dropdown)

How to show polygon data in Power BI:

Open or create a Power BI project that has a web connection to Neighborhoods of a project session. See this How-to;
Select the visuals tab in your Power BI Project
Click on the triple dots icon named "Get More Visuals" and select the option "Get More Visuals".
In the search field, type "Icon" and select the "Icon Maps" app.
On the Icon Map app page, click on the "Add" button.
Unfold the "Neighborhoods" data connection
Find and drag the features.properties.NAME attribute to the Category field.
Select a numerical property, such as feature.properties.ACTIVE and drag it to the Size field.
The Icon Map should now show a map, but not yet the shapes of the neighborhoods.
Select the "Format your visual" tab and unfold the GeoJSON section.
Click on the Off button to activate it.
Switch to the Tygron Client Application to a Neighborhood GeoJSON endpoint.
Select Current Situation in the Ribbon bar
Hover over Administrative and under Neighborhoods, select Export Geo data.
In the Export Geo Data panel, set the type to GeoJSON (MultiPolygons).
Verify that the export CRS is set to 4326. If not, click on the edit link.
In the CRS selection panel, type 4326 and press enter.
Wait for the process to finish and select the WGS84 CRS with the number 4326 and confirm with select.
Click on the Copy URL button next to GeoJSON endpoint.
Switch back to Power BI and paste the link in the URL field in the GeoJSON we had previously activated. (Use CTRL-V)

Notes

In the format section of Format your Visuals, you can also customize the coloring of the shapes based on the value of a feature property.
Icon Maps currently only seem to be able to visualize GeoJSONs exported using the CRS 4326.