Cant add template in destination field

[AlanMW]

I have a destination that is variable based on my calendar, I can't seem to update the destination with that value. Some of the templates I have tried:

'{{state_attr('calender.activities', 'location') | string}}'
'{{state_attr('calender.activities', 'location')'

I am guessing the input doesn't support templates?

type: custom:ha-card-waze-travel-time
header: false
name: Current Drive Time...
unit: mi
columns:
  - from
  - to
  - duration
  - distance
  - icon
destinations:
  - entity: sensor.waze_travel_time
    from: Home
    to: '{{state_attr('calender.activities', 'location') | string}}'
style: |
  ha-card {
    --primary-text-color: #FFFFFF;
    --secondary-text-color: [#727272](https://github.com/r-renato/ha-card-waze-travel-time/issues/727272);
    --text-primary-color: #ffffff;
    --disabled-text-color: #bdbdbd;
    background-image: url("/local/imgs/card_back.png") ;
    background-repeat: no-repeat ;
    background-color: rgba(50,50,50,0.3) ;
    background-size: 100% 300px ;
    border-radius: 20px ;
    border: solid 1px rgba(100,100,100,0.3) ;
    box-shadow: 3px 3px rgba(0,0,0,0.4) ;
  }