I would like to ask if there is a way to create a map of accessibility-service areas from GTFS data in QGIS. For example, where can I reach by public transportation from a stop within 30 minutes, 45 minutes, 60 minutes, etc. In ArcGIS, it is straightforward, and there is a GTFS toolset (https://pro.arcgis.com/en/pro-app/3.1/help/analysis/networks/create-and-use-a-network-dataset-with-public-transit-data.htm). However, I have searched, and in free platforms like QGIS, I haven't found anything similar.
I attempted to create a Python script for the calculation, but unfortunately, it was unsuccessful. Additionally, I searched for a QGIS plugin to streamline the process, but I couldn't find a suitable one. I am seeking guidance on how to perform isochrone analysis and visualize public transportation accessibility from GTFS data in QGIS.