Unable to create coupons via Wix API due to authentication errors, despite having all permissions; manual creation is slow and repetitive

I’m having trouble with:
I’m unable to create coupons via the Wix API. I keep getting authentication errors even though my API key has all permissions.

Working in:
Wix Ecommerce API / Automation tool

Site link:
[Insert your live or test site link here]

What I’m trying to do:
Automate the creation of coupons for my Wix store to save time and avoid repetitive manual entry.

What I’ve tried so far:

  • Checked that my API key has all required permissions

  • Attempted multiple API requests

  • Verified that the Coupons app is installed and authorized

Extra context:
Errors received:

  • Authorization failed - please check your credentials

  • Coupons App is not installed or unauthorized
    No changes to API settings appear to resolve the issue.