In the UA document it looks like it is an action, on here it is a bonus action

Because the D&D Beyond devs made a mistake.

Even the WotC devs made a mistake with the spell - in the UA document it lists this as a target: "Self (15 ft cone)" but in the description it says 30 ft cone. 

So what is the real information? 1 action, 30ft? 1 action 15ft?

Quote from Tdelouis >>

So what is the real information? 1 action, 30ft? 1 action 15ft?

 
1 action, range says cone 15ft while description says cone 30 ft.

We will not know if it's 15 ft or 30 ft until WotC update or publish it.

And remember, D&D Beyond is not WotC, so D&D beyond cannot tell you what it is meant to be.

This discrepancy in casting time has been passed along

I'm assuming it's a self spell with a 30ft cone that takes your action