Enable alarm in Shortcuts
When Shortcuts first came out, I immediately created a Sleepytimes script. Among other things, it enabled Do Not Disturb. After some days of use, I realised that you could also add controls over Bedtime.

The two steps you are looking to do go like this.


Add the object Set Do Not Disturb. Set it to ON and the Until to your liking.
Add the object Edit Bedtime (search for it - if you cannot find it, just launch Clock -> Bedtime a couple of times - hopefully there will be an easier way to get this to show in the future).


Hope this helps! Also, I think I can just share a shortcut with Edit Bedtime in it. Let me know if you are able to access Edit Bedtime by opening this iCloud link - after that you could try and tap on the object and select "Set favorite". Would be interesting to see if this lets it show for you from now on in the searches or in the Favorite -tab?

https://www.icloud.com/shortcuts/54661787f1584383bf2c369507222382