Post-Purchase redirect after order confirmation to candidly instead of thank you page

[VicBrew1]

Hi everyone! 

Store: https://qtupb6-n1.myshopify.com/

I'm trying to redirect someone after purchase to my candidly site so that they can book some free time with me instead of going to the thank you page. 

I've read through a lot of Shopify's notes and found that the starter/basic plan doesn't allow (if I understand correctly) modification to the flow of purchase. There has to be a way to do this. I would love to have it as an upsell but fearful that someone would forget to attach the item to their purchase and it is a needed item for each purchase. it is it's own separate product because someone may purchase just a consultation if they are not looking to buy any services yet. 

So far I've looked into: 

https://shopify.dev/docs/apps/build/checkout/product-offers

https://shopify.dev/docs/apps/build/checkout/product-offers#post-purchase-product-offers

https://help.shopify.com/en/manual/checkout-settings/customize-checkout-configurations/checkout-exte...

https://shopify.dev/docs/api/checkout-ui-extensions/2024-10/configuration

But I'm a bit confused as to how to start. There's a lot of talk about extensions and coding them in but no lines of code just bin files that I don't want to mess up. 

Currently installing and going to try the following and see if it works: Kwik- COD 

I would prefer to get help with some code to do this instead of paying for an app. Thank you for your time!

[VicBrew1]

Update: I've been trying the redirect URL option in Navigation settings but no luck as each /thank-you page URL is unique 

[VicBrew1]

I'm assuming this is where I can add code to make to turn the continue button into a book time button and forward the customer to candidly BUT I am no expert coder, so I have no idea where to go from here.

The name of the button: