how to read file content into template literal ?

[dili-world]

code

hello.html

hello ${username}

main.ts

let username = "john";
const data = await Deno.readFile("hello.html");
let bodyContent = decoder.decode(data);
bodyContent = `${bodyContent}`;// i want to let the bodyContent put into template literal
console.log(bodyContent); //output is "hello ${username}",  how to output "hello john" use template literal?

or

let username = "john";
let fileContent = "hello ${username}";
let template= `${fileContent}`; 
console.log(template);