Zoho Commerce & Javascript Expert

Looking for someone very knowledgeable with Zoho Commerce and Javascript to create automation.

Some products purchased on a site require professional installation, and I need to automate the appointment booking process based on customers location. The required process looks like this:

1 - Customer adds a product to the cart that they want installing
2 - Then selects the shipping option at checkout (we have a shipping option for each area we install in)
3 - Customer pays for the physical product, then gets redirected to the standard Commerce payment status page

The payment status page is where I need to implement the automation. Each shipping option has a unique URL (going into a Zoho Bookings appointment page). The 'continue shopping' button on the payment status page needs to be changed to 'book appointment', then when customers click this button, they'll be taken to the unique URL that matches the shipping option selected at the checkout.

Currently, I have code in the header section of the site that triggers one shipping area to work this way, but I can't work out how to replicate the action to the other areas, or change the 'continue shopping' button to 'book appointment'.

I really need someone who knows exactly what they're doing and I also need this done today! So please, only submit a proposal if you're confident you can get this working in the next few hours :)