Upload test reports to merge requests

Hi team,
I’m using GitLab together with Bitrise, and my current workflow for the merge requests look like this:

  1. MR is created
  2. Workflow is triggered on Bitrise
  3. Workflow finishes on Bitrise, MR pipeline status is updated on GitLab

This works fine, however I’m missing the test reports being automatically attached to the MRs when I used gitlab-runner. So my question is, is it possible to somehow upload the junit (or any other artifact) and attach it to the MR? I checked the gitlab-runner docs and there are 2 commands marked as internal there, that seem to be responsible exactly for that, but I just want to make sure that this is indeed a way to do it. Or perhaps there is a way to achieve this through the API (I checked the API but didn’t find anything like this in the docs)?