Need help setting SSH between bucket and deployment server

I inherited duty of maintaining a project (simple bugfixes), but it turns out I must first fix deployment pipeline after server migration (which I didn’t know I’m signing up for…)

PROBLEM: bitbucket (cloud) can’t establish SSH connection with the server (another cloud)

Here are steps I’ve taken:

  1. generate key, add it, and put it in config, test connection (scr 1)
  2. put public key in bitbucket (scr 2 3)
  3. reconfigure develop part pipeline to point to new server (scr 4)
  4. when trying to build the project I get error (scr 5)

SCREENSHOTS:
https://drive.google.com/drive/folders/1VkjNTvcIw66meOCelVFOnbG30GoQqBko?usp=sharing

I’m 99% convinced, that the pipeline definition is missing sth. Any suggestions are much appreciated, as I exhausted all the ideas I had.

Thanks
Rafał