I need to press the "Play" button

My code: cy.get('.button.button__slider-play.button__rounded-xl').should('be.visible').click();
But I have response : Timed out retrying after 4000ms: Expected to find element: button.button.button__slider-play.button__rounded-xl, but never found it.
Assuming there is no iframe or shadow DOM, you can do like this:
cy.get('button[class*="slider-play"]).should('be.visible').click();
In case, click doesn't work you can use click({force: true})
cy.get('button[class*="slider-play"]).should('be.visible').click({force: true});