The deployments fail with Cannot read property 'url' of undefined

[michalczaplinski]

I'm using the action in my workflow

The deployments have started to fail with:

✖  fatal     TypeError: Cannot read property 'url' of undefined 
    at /index.js:55:42
    at processTicksAndRejections (internal/process/task_queues.js:97:5)

In fact you can see the result of the github action right here: https://github.com/frontity/frontity.org/pull/107/checks?check_run_id=676275381#step:7:8

There's nothing in the main index.js file for this action that seems to me indicate the source of this error so any clue on what that might be?