Hi Zachary,
We do not support programmatic cell selection in the HeatMap
component. Instead, we only allow cell selection via UI interaction when the "allowSelection"
API is enabled.
Meanwhile, in the sample below, the HeatMap component is
generated for each Pivot Table component's cell selection. Does this meet your
requirements, or do you simply want to select cells in the existing HeatMap component
based on any external action on the web page?
https://ej2.syncfusion.com/javascript/demos/#/bootstrap5/pivot-table/external-binding.html