Hello, Trying to create a recursive function to count the letter “B” but every time the output says 1 no matter what string i gave [duplicate]

function countB3(string, position = 0, count_letter = 0, count = 0){
    if(position < string.length){
        if(string.charAt(position) == 'B'){
            position ++;
            count_letter ++;
            countB3(string, position, count_letter)
        }else{
            position ++;
            countB3(string, position, count_letter);
        }
    }return count_letter
}

This is the code, Idk why the output when i console.log is always 1 no matter what, i manage to do it with a for loop but no idea here….