Narrator supports navigation by headings. See support article that describes how to cycle through navigation modes.

Text with style: heading receive the appropriate accessibility flags on other platforms to support this mode of navigation, including UWP XAML. However, the .NET WPF renderer doesn't seem to offer this support (see details in microsoft/AdaptiveCards#5626).

Consult with accessibility team to determine if there is a workaround, or close this as external.