Hello, dear oksana82.
I hope you are doing good today.
When you add video from Vimeo, it automatically creates an image. But if you want to change the image, you just need to click on the “Add Image” button. There you can add an image from the image library and save it. After that, the page will show what you added to the galleries.
Have a good day!
Sincerely, Total-Soft
