How to create YAML variables?

I would like to be able to have a String variable like you would In java that I can change and implement into some YAML command I have, but I’m not sure how to do it or if it’s even possible.

I’m trying to create a card on my desktop dashboard where I can drop a youtube link and press launch and it will open on my TV. This would be done using ADB, I have the command working, but only with a link that I put in the code. Is there a way to have this part of the code be a variable that I can fill? How would I implement that??

Here’s the YAML:

service: androidtv.adb_command
data:
  command: >-
    am start -a android.intent.action.VIEW -c android.intent.category.BROWSABLE
    -d "https://www.youtube.com/live/pt4qkWORaRQ?si=GA3T0cZ3wCwrbycD"
target:
  entity_id: media_player.fire_tv_adb

So that link I just want to make a variable that I can fill with different links…

Then:

data:
  command: >-
    am start -a android.intent.action.VIEW -c android.intent.category.BROWSABLE
    -d "{{ states('input_text.YOUR_ID') }}"

Hey this worked, how do I do == in yaml with strings, EX:

I figured it out! {{ states('input_text.youtubelink') == "Enter Text Here"}}