Hey Cesar ,
Thanks for reaching out to us, hope you've had a great weekend! Apologies for the delay in our reply, there were some holidays in The Netherlands.
All actions will open the default app. If you're using your desktop/PC, make sure that you have standard apps installed and set up. You can read more about that in this discussion here: https://community.buttonizer.pro/d/885-the-email-button-doesnt-work
On phones, Buttonizer it will open the default apps that are installed on the device. Were you trying out the button action on a phone or on desktop?
Hope it helps 🙂