3 x mortgage calculator forms for Joomla 4 website

I need replicas of these calculators to embed on a Joomla 4 website. I'd prefer 1 x js file for the scripts, and the forms themselves separate, but if not inline javascript is acceptable. CSS to be handled by the bootstrap environment. Here are the 3 examples I need:
• Repayment calculator:
I like the option of running 2 calculators beside one another. See:
https://homeloanshop.co.nz/how-much/mortgage-repayment-calculator/
• Overpayment calculator:
https://www.moneysupermarket.com/mortgages/overpayment-calculator/
• Investment property return calculator:
https://www.themortgagegirls.co.nz/resources/investment-return-calculator/