New file on Google Drive to Google Calender entry (date entry error)

Hello to all, I am very new to this and wanting some help from someone who can tell what I need to do.

I want to create a calender entry on my Google Calender whenever a new file is added to my drive. I have linked my drive and linked my calender, I have set up the flow to watch my drive and it successfully recognises new files, yippee it works.

I have also figured out how to get it to display the file name and file link in the calender title and description. However I cannot for the life of me figure out how to set a varible time to ad the event?!

I have tried {{steps.trigger.context.ts}} and {{steps.trigger.event.createdTime}} in each of the time Event Date and End date boxes, I have tried using both in each and sdifferent ones in each, but all I get is an error;

Bad Request ```
   at global.handleError (/var/task/common.js:39:40)

I’m guessing this is to do with the date, when I enter the date manually ie todays date in the required format it works.

Can someone help me on what I need to do to get to the date correct so it can display updates on my calender.
TIA.