[PLEASE, DELETE IT] Trigger list of pipelines through the API

Question about CI and Triggering pipelines through the API

I have core module and a bunch of services (let’s say 20).
Services depends from core and they need to be rebuild each time core is changed.

each time pipeline runs on core module it should trigger pipeline on each services.

It can be done with API, we can just add this line to our core pipeline:
- curl --request POST --form token=$API_TOKEN_SERVICES1 --form ref=demo $SERVICES1

Where $API_TOKEN_SERVICES1 stores in core projects Environment variables,
and $SERVICES1 are URL to service #1.

I don’t want to list all the URL services in .gitlab-ci.yml, I want different file with list of this services.
I tried to use bash script with 20 lines of
curl --request POST --form token=$API_TOKEN_SERVICES1 --form ref=demo $SERVICES1...
But problem is that bash script doesn’t catch $API_TOKEN_SERVICES1 variable (because it stores in projects environment variables).
I also can’t store API_TOKENS in files because it is not secure.

What I want to achieve:

  1. In core project I need pipeline which will trigger list of pipeline services.
  2. List of this services should be on different file, not in .gitlab-ci.yml

How can I achieve this?

Thank you for your help.