> you have to first generate a screenshot by running your suite with --update-snapshots.

How is it executed? Is it something build in into the Playwright, or there is missing part of the code presented, responsible for executing it?

Ah forgot to mention it in the post. This comes built in by Playwright. Normally, you invoke the test suite by running `npx playwright test`. This fails your test if a screenshot is missing or if it differs. By running `npx playwright test --update-snapshots` you tell Playwright to just overwrite the snapshots and not fail tests.