Add a link to a menu, by the name of the menu, through its "Add link" form: the title of the link and the path it leads to ("about", "node/5", "<front>" or a full address).
Examples
When I add the link "Notes" to "about" in the "Primary navigation" menu
When I add the link "Hours" to "opening-hours" in the "Primary navigation" menu
When we add the link "Start" to "<front>" in the "Primary navigation" menu
And I add the link "Project" to "https://example.com" in the "Primary navigation" menu
When add the link "Account" to "user" in the "Account menu" menu
Pattern
When(/^(I |we )*add the link "([^"]*)" to "([^"]*)" in the "([^"]*)" menu$/, …)
Part of @webship-js/backdrop-cms-steps (github.com/webship/backdrop-cms-steps), a step pack for Webship-js 2.0.x.