For a wordle clone on code.org, how can I make it so that words that are in the right spot/in the word turn yellow?

So I am making a wordle clone in code.org using the dataset, yet I am facing two issues.

The first issue is that when I console.log the correct answer, sometimes it says “null” and other times it works without issue.

The second problem is I don’t know how to make the words yellow if they are out of order or in the word. My code is down below.

//Getting Wordle Answer 
var answers = getColumn("Wordle", "validWordleAnswer");
var index = (randomNumber(0, answers.length));
console.log(answers[index]);
var letters =  ["letter1", "letter2", "letter3", "letter4", "letter5"];


    //Checking Words
    onEvent("wordbutton", "click", function( ) {
      var guess = getProperty("wordInput", "text");
      for (var i = 0; i < 5; i++) {
       
    
         if (guess == answers[index]) {
              setProperty(letters[i], "background-color", "green");
            } else if ((answers[index].includes(guess))) {
              setProperty(letters[i], "background-color", "yellow");
            } else {
              setProperty(letters[i], "background-color", "red");
            }
        setProperty(letters[i], "text", guess[i]);
      }
    });

Specifically the else if statement, and the first four lines of code that are my variables