According to the information in the theme’s documentation, the image should be 1920 x 750 pixels. If the image is from the media library, after you select the image, click the edit image button on the lower left side of the page below the image. In the top left side of the menu is the crop tool. Click on it and put you mouse on the image and drag your mouse to create a cropping window. Over to the right is the image crop area, under the selection section, change the first number in the left selection box to 1920. In the right box put in the 750 number. This will resize the crop window. Go over to the image and move the box around the image until you are satisfied with what you see in the highlighted box. This is what will be cropped out of the image. When satisfied, click the crop tool again. and then click the save button. Your image should now be the correct size for the area provided in the Match theme. Hope this helps answer your question. Best of luck.
