Since Kagi maps doesn't have live navigation available, we need to exfiltrate the result into another mapping application like Magic Earth, Here WeGo, Mapquest, Apple, or Google to do in-vehicle navigation.
All of these respect the standard geo link format as a paste-in.
As is, the text address needs to be manually highlighted and fought with to wrangle into another application.
Searching for a location in Kagi maps on mobile, then attempting to navigate to there while in-vehicle, using car navigation software (Android Auto, CarPlay)