Storing upper and lower numbers from user input

I am trying to store the lower number and the upper number from user input, but I am having a logic error. My code runs without error, it generates a number, but not within the range I have set.

var lowerNumber = window.prompt("Enter the lower range number for the random number generator"); var upperNumber = window.prompt("Enter the upper range number for the random number generator");

function getRandom(lowerNumber,upperNumber) {

return Math.floor(Math.random() * (upperNumber - lowerNumber + 1)) + lowerNumber; }

console.log(getRandom(lowerNumber,upperNumber));

I was also wanting to store the random number into a variable and show that but I also had syntax errors with that. For example, using this code in my function

const randomNumber = Math.floor(Math.random() * (upperNumber - lowerNumber + 1)) + lowerNumber; return randomNumber

console.log(Your random number is ${randomNumber});