If you want to scan a local application, ngrok might seem like a possible solution. However, it's currently not possible to use ngrok in particular with Detectify, due to the low request limit: At the time of writing this article, ngrok implements a limit of at most 120 connections per minute. The lowest possible setting in Detectify is 5 requests per second, or 300 requests per minute. This leads to a major loss of traffic and consequently a failure to provide adequate testing coverage during the scan.
However, if you are using an ngrok-like service with a higher request limit, it is possible to use it with Detectify to scan local applications.
If you need any help setting it up,