How do I generate a string that contains a keyword?

I'm currently making a program with many functions that utilise Math.rand(). I'm trying to generate a string with a given keyword (in this case, lathe). I want the program to log a string that has "lathe" (or any version of it, with capitals or not), but everything I've tried has the program hit its call stack size limit (I understand exactly why, I want the program to generate a string with the word without it hitting its call stack size).

What I have tried:

function generateStringWithKeyword(randNum: number) {
  const chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789+/";
  let result = "";
  for(let i = 0; i < randNum; i++) {
    result += chars[Math.floor(Math.random() * chars.length)];
    if(result.includes("lathe")) {
      continue;
    } else {
      generateStringWithKeyword(randNum);
    }
  }
  console.log(result);
}

This is what I have now, after doing brief research on stackoverflow I learned that it might have been better to add the if/else block with a continue, rather than using

if(!result.includes("lathe")) return generateStringWithKeyword(randNum);

But both ways I had hit the call stack size limit.