Search for a term by filling the keyword field (input[name="keys"], the name the Search module uses for both the search block and the search page; the "search input" named selector) and submitting. On a site without the Search module the step says so.
Examples
When I search for "webship"
And we search for "cucumber"
When search for "playwright"
And I search for "sample title"
When we search for "example"
Pattern
When(/^(I |we )*search for "([^"]*)?"$/, …)
Part of @webship-js/drupal-cms-steps (github.com/webship/drupal-cms-steps), a step pack for Webship-js 2.0.x.