Building in Docker, Firmware could not be created. Platform ID not a match

I am using the following docker container to compile my firmware: https://hub.docker.com/r/particle/buildpack-particle-firmware.

Where the platform ID is 6 - I am using the same steps in the Docker readme.

After building I attempt to upload the firmware to my Product dashboard, so I can distribute to my fleet and I get the below error:

Bummer! Your firmware could not be created. The platform id in the binary must match the product platform id

My library.properties file has the architectures=dependent on particle-electron. And the main.ino lists the product version and product ID correctly. What other change do I have to make?

Note this post is different: Bummer! Your firmware could not be created. The platform id in the binary must match the product platform id. I am not using the IDE.

Electron has platform ID 10 instead of 6 for Photons.

Thanks. I must have missed this in the Docs.