How to specify environment variables in the project.yml file for App Functions?

I am trying to specify two environment variables that are needed to perform some functionality on my application. I try to specify them as follows:

services:
    envs:
    - key: MY_FIRST_VAR
      scope: BUILD_AND_RUN_TIME
      value: a_key_value
    - key: A_UNIQUE_KEY
      scope: BUILD_AND_RUN_TIME
      value: 123456789asdf

packages:
  - name: sample
    actions:
      - name: hello
        runtime: 'python:default'

I tried to mimic what I saw here

When I try to build, though, I get a message:

›   Error:   : Invalid project configuration file (project.yml): Invalid key 
›   'services' found in project.yml

I have tried mixing things around and trying different combinations, however I’m stuck as to how to go about this. I tried defining the environment variables through the GUI, however they were not recognized by my python program that needed them.

If you need any other information for about this to help let me know!