Many of the fair use images found using the above Google Image search method have Creative Commons licenses. Here is more info:
Searching for images in Google Slides
You can find your book cover in either of these resources.
You can enlarge the image or not.
Then right click the image and either choose "Save image as" saving the photo to your desk top or "Copy the image address" - either way allows you to then insert the image into your slides.
Be sure to cite the image source on the slide it appears on.
The following information was created by Maria Barakovskykh of SCF Libraries, State College of Florida Manatee/Sarasota:
Images, diagrams and other visual artistic works should be cited as any other type of work. Below are some examples:
Try to find as much information as possible when citing an image and include it in the citation.
Artist Last Name, First Initial. Second Initial. (Year). Title of the artwork [Format]. Retrieved from URL.
Title of work [Type of work]. (Year image was created). Retrieved from URL
[Subject and type of work]. Retrieved from URL
Note: You still need to cite the image even if you are missing much of the information. Please try to find images that do provide this information.
Go to the original location (website) of the image and cite in one of the formats above.
EXAMPLES:
Note: Each Retrieved from source name is hyperlinked to the original page the image resides on
Public domain photo cited
Miller, Shawn. (2017). National Youth Poet Laureate Amanda Gorman reads her work, "An American Lyric," at the inaugural reading of Poet Laureate Tracy K. Smith [Photo]. Retrieved from: commons.Wikimedia.org
Copyrighted photo cited for educational fair use
Meyer, Maddie/Getty Images. Mookie Betts [Photo]. Retrieved from Forbes online
Fan art with some rights reserved, cited according to cc license
Angie22Arts. Twilight Fan Art [Image]. Retrieved from: Flickr
Example of book cover citation
Image retrieved from NOBLE Catalog