import { createAdminClient } from '@spree/admin-sdk'

const client = createAdminClient({
  baseUrl: 'https://your-store.com',
  secretKey: 'sk_xxx',
})

const rule = await client.promotions.rules.update('promo_UkLWZg9DAJ', 'promorule_k5nR8xLq', {
  preferences: { currency: 'USD' },
})

spree api patch /promotions/{promotion_id}/promotion_rules/{id} -d '{"preferences":{"currency":"USD"}}'

{
  "id": "prorule_UkLWZg9DAJ",
  "created_at": "2026-01-15T12:00:00.000Z",
  "updated_at": "2026-01-15T12:00:00.000Z",
  "type": "currency",
  "promotion_id": "promo_UkLWZg9DAJ",
  "preferences": {
    "currency": "GBP"
  },
  "product_ids": null,
  "category_ids": null,
  "customer_ids": null,
  "option_value_ids": null
}