If you want to unburden users from manually entering the promo code that they've received, you can utilize one of the 2 below options to have the promo code automatically pre-filled in checkout.
1. Include the promo code as an URL parameter. For example, when a user clicks on an email link with an offer, they will be redirected to a page with the promo code parameter already filled in. Please note, that on this page, the offer will need to be presented.
For example https://website.com?promo_code=PROMO123
2. Show an offer programmatically using JavaScript and include the promoCode parameter, like this:
tp.offer.show({
offerId: "<offer_ID>",
templateId: "<template_ID>",
displayMode: "modal",
promoCode: "<promo_code>"
});
For example, below is a code snippet with real values. You would just replace the values with the ones from your Piano dashboard.
tp.offer.show({
offerId: "OFPRLHTJMQPB",
templateId: "OTDKTCUTXMPL",
displayMode: "modal",
promoCode: "PROMO123"
});
More information on manually triggering offers with JavaScript can be found here.