How variables can be used in javascript?

[zenglihunter]

My code in JavaScript block is this
document.querySelector('kat-textarea').value = 'dear {{ variables@name}}, nice to meet you!';

But it only outputs text, how can the variable parameters take effect?
For example:
dear {{ variables@name}}, nice to meet you!
is
dear tiger, nice to meet you!

thank you

[zenglihunter]

var name = automaRefData('variables', 'name');