A UIActivity Helper Class to show thumbnail preview and text in the share sheet title area

ItemDetailSource.swift

//
//  ItemDetailSource.swift
//  StickerTweet
//
//  Created by Swapnanil Dhol on 7/9/20.
//  Copyright © 2020 Swapnanil Dhol. All rights reserved.
//

import UIKit
import LinkPresentation

class ItemDetailSource: NSObject {
    let name: String
    let image: UIImage

    init(name: String, image: UIImage) {
        self.name = name
        self.image = image
    }
}

extension ItemDetailSource: UIActivityItemSource {

    func activityViewControllerPlaceholderItem(_ activityViewController: UIActivityViewController) -> Any {
        image
    }
    func activityViewController(_ activityViewController: UIActivityViewController, itemForActivityType activityType: UIActivity.ActivityType?) -> Any? {
        image
    }

    func activityViewControllerLinkMetadata(_ activityViewController: UIActivityViewController) -> LPLinkMetadata? {
        let metaData = LPLinkMetadata()
        metaData.title = name
        metaData.imageProvider = NSItemProvider(object: image)
        return metaData
    }
}

UsageForAbove.swift

//Code used for StickerCards. Please make changes as neccesaary.     

private func saveCardWithBackground() {
        guard let stickerImage = generateCardWithBackground() else { return }
        let ac = UIActivityViewController(activityItems: [ItemDetailSource(name: "Tweet by \(tweet?.name ?? "Unknown")", image: stickerImage)], applicationActivities: nil)
        if let popoverController = ac.popoverPresentationController {
            popoverController.sourceView = self.view
            popoverController.sourceRect = CGRect(x: self.view.bounds.midX,
                                                  y: self.view.bounds.midY,
                                                  width: 0,
                                                  height: 0)
            popoverController.permittedArrowDirections = []
        }
        self.present(ac, animated: true)
    }

Thanks, very helpfull