How do I attach a discount voucher to a Facebook post posted from my website>

[NigelFitt]

My name is Nigel Fitt

My email address is nigelynguestcottage04@gmail.com

My website URL is https://nigelynguestcottage.weebly.com

I have a Facebook Page and a website. I have a Facebook Like and Share button on nearly every page of my website. I want to add a discount for my business to posts on Facebook from my website. I would like to make it so that people can download or save the voucher so that they can print it to give to me so that they can receive their voucher. I would like the voucher to be attached to my posts when my contacts share my posts with their contacts.

[Adam7]

I'm not sure if you can attach something like that to Facebook posts as an attachment. You could make coupon codes and include those with Facebook posts, though.