@aidensala use webbrowser with url scheme of the app you want to start, like
import webbrowser url = 'mailto:' webbrowser.open(url)Edit: if the url is an http, script will open a browser in Pythonista. Else, it will open the asked app.
Edit: but why do you need base64?
Edit: example, to open the iOS Shortcuts app and run a shortcut named "Make PDF"
url = 'shortcuts://run-shortcut?name=Make%20PDF'