Go to Campaigns > Create New Campaign.

Select Text and Coupon.

Name the coupon. This name is internal only — customers never see it.

Set the gift: a dollar-amount discount (for example, $1–$10 off), and optionally make it conditional on a minimum purchase (for example, must spend $30+).

If the coupon is delivered as a tap-through link, you don't need to require a promo code.

Set an expiration: either a specific date/time, or leave it blank and instead restrict by recurring availability (for example, only valid Tuesdays, midnight to midnight).

Create or upload a coupon graphic image for the text message.

Save the campaign.