How to change Size Featured Slider

Hi Everybody
How to change Featured Slider in theme Travelify.
Default size slider is 1018px x 460px
i want change size to: 1280px x 720px
Please help me.
Thank you.

Hello there,

I hope you are doing well today.

You would have to change the theme files via Appearance > Editor > Theme Functions and search for "add_image_size( ‘slider’, 1018, 460, true ); " and change the values there.

It is best to make a backup before making any changes:

Best Regards,
Support

Hi…
Thank you…
I did that. But it’s does not work.
Sorry i’m form Vietnam, so my english is so bad.

Thank you so much
Best Regards!!

Now, try to add new images to the slider or run regenerate thumbnails plugin: Regenerate Thumbnails – WordPress plugin | WordPress.org