Troubleshooting Your ROI Calculator: Seeking JavaScript Help

I'm so lost trying to build an ROI calculator. To be 100% transparent I used ChatGPT and it told me to make a form and then add the given JS. Paste the JS into the </body> part of my site. But it's not working what so ever. Any thoughts? https://preview.webflow.com/preview/llxyz?utm_medium=preview_link&utm_source=designer&[…]&pageId=667f27bd1ec54c1767c7bf0f&locale=en&workflow=preview