How can I enable a 'Pay it Forward' option at checkout on my Dawn-themed store?

I want to give away a product for free. After someone checks out, I would like to give them the option to “Pay it Forward” to someone else.

so… they would receive it for free because someone else paid for them. I’d like to then give them three options to “Pay it Forward” for 1) one individual, 2) a small group or 3) an entire community. These would essentially be three different giving tiers to donate to the non-profit (after they received their gift for free).

This is the way Angel Studios funded The Chosen and how movies like The Sound of Freedom grew so quickly. I would like to do this with a physical product (for a non-profit).

How is this possible? (My store is built using the Dawn theme, if this matters)

Hi Simka, I was a little confused about your question.
Free selection: If you want to send something to others you can just write their shipping address and you can pay for it

Pay It forward selection: maybe you can create a wishlist and share the url to three different giving tiers

Allow me to clarify:

The product in my store costs $0.00 because I want to give it away. After someone checks out and completes their purchase, I want them to have an option to pay to give one to someone else (i.e. donate to the charity that is giving them away for free).

I have the software solution to allow for the donations. Perhaps an easier question to answer is:

How do I customize what someone sees after checkout is complete in Shopify? (If I can control this, I can provide the option to donate through DonorBox.).