Function add_group_gallery_image 

pub async fn add_group_gallery_image(
    configuration: &Configuration,
    group_id: &str,
    group_gallery_id: &str,
    add_group_gallery_image_request: AddGroupGalleryImageRequest,
) -> Result<GroupGalleryImage, Error<AddGroupGalleryImageError>>

Adds an image to a Group gallery.