Store base64 String to file and share it

ShareBase64PDF.swift

import UIKit

class ViewController: UIViewController {
    
   @IBAction func sharePDFActionButton(_ sender: Any) {
        do {
            try savePdf()
            loadPDFAndShare()
        } catch  {
            print("FALLO EL GUARDAR EL PDF")
        }
    }
    
    let pdfString = "Put your base64 encoded PDF here"
  
    override func viewDidLoad() {
        super.viewDidLoad()
    }
    
    func savePdf() throws {
        let documentsURL = try FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
        let pdfDocURL = documentsURL.appendingPathComponent("document.pdf")
        let pdfData = Data(base64Encoded: pdfString)
        try pdfData!.write(to: pdfDocURL)
    }
    
    func loadPDFAndShare(){
        do {
            let documentsURL = try FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
            let pdfDocURL = documentsURL.appendingPathComponent("document.pdf")
            
            let document = NSData(contentsOf: pdfDocURL)
            let activityViewController: UIActivityViewController = UIActivityViewController(activityItems: [document!], applicationActivities: nil)
            activityViewController.popoverPresentationController?.sourceView=self.view
            present(activityViewController, animated: true, completion: nil)
            print("document was not found")
        } catch  {
            print("document was not found")
        }
    }
  
}

This is actually a brilliant solution!