If a custom node requires a ENV variable, you can do this by adding a docker command to your machine. For example such as OpenAI key for this custom node,
Docker commands are those that you would write in a Dockerfile reference.

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Steps

  1. Edit or create your machine definition.
  2. Scroll down to Extra docker commands section.
  3. Add and modify the command
ENV VARIABLE_NAME=<value>
  1. Save your machine definition
This machine will then have VARIABLE_NAME as an env variable.