via e-mail:
In the docs where you mention “Journey planning - Westminster to Bank”, you have 2 examples:
ex 1: https://api.tfl.gov.uk/journey/journeyresults/westminster/to/bank
ex 2: https://api.tfl.gov.uk/journey/journeyresults/1000266/to/1000013
My app already retrieve the list of your stations and their geo location from your kml file, and to do API calls it would be better to use numbers instead of the stations name.
I don’t know if they are called NapTan codes.
I have tested the following url https://api.tfl.gov.uk/journey/journeyresults/allsaints/to/aldgate, and it seems to work, but i’m afraid that by only using the names some errors might happen if they are not exactly the same.