Welcome!
If you use the “smartthings classic” app instead of the “smartthings (Samsung connect)” mobile app, you can set up a widget, although you will need one to unlock the lock and one to lock the lock.
https://support.smartthings.com/hc/en-us/articles/206145893-Is-there-a-SmartThings-widget-
If you have an android phone, there are some additional options as well, but they require adding a third-party app.