No stages / jobs for this pipeline - Trigger multi staging pipeline

Hello,
I am trying to trigger a multiple pipeline job where project A makes a post on B after a push to the master branch, where B will run some tests on the code of A.

gitlab-ci.yml of A:

image: alpine

stages:
  - setup

start_evaluation:
  stage: setup
  script:
    - apk add --no-cache curl
    - curl --request POST 
      --silent
      --form token=${CI_JOB_TOKEN}
      --form "ref=master" 
      --form "variables[PROJECT_URL]=my_url" 
      --form "variables[PROJECT_ID]=my_id" 
      "$WEB_API"
  only:
    - master

When the pipeline runs I get:

{"message":{"base":["No stages / jobs for this pipeline."]}}

So any advice can be good for me. I’ve searched around and even tried the trigger on the yml as on this doc and didnt worked. (Dont recall the error though)

I am using gitlab.com =D

Hello,

Did you resolve your problem ? I’m interested on