Github Action: Split Long Command into Multiple Lines

I have a multi line command using backslash to separate the lines as follows:

- name: Configure functions
  run: |
    firebase functions:config:set \
      some.key1="${{ secrets.SOME_KEY_1 }}" \
      some.key2="${{ secrets.SOME_KEY_2 }}" \
    ...    

Note the preceding ‘|’ character.