How to get my card ID for API calls?

[cohereandnow company]

I am setting up an API call that comments on a card. I have the two parameters "id" and "text" as shown in the documentation on https://developer.atlassian.com/cloud/trello/rest/api-group-cards/\#api-cards-id-customfielditems-get.

I see in the documentation that the cards id looks like this "^[0-9a-fA-F]{24}$" but I cant seem to find a card id that looks like that.

I tried "idCard" and "id" as the key and the following card value from the cards url: "yrSLWrI9".

When I test it, I get a 400 error code "invalid id". How I can get the card id that can be used in an API call?

[milynnus]

@cohereandnow company 

The variable is {cardidlong}