A collection of error codes from Ecster
Error: Ecster Pay create cart request failed 4001 (false does not match pattern httpOrHttpsUrl for parameter shopTermsUrl).
This means that you have not set a terms and condition page in WooCommerce.
Go to WooCommerce > Settings > Advanced and then go to the Page Setup section and make sure you have set a Terms and Condition page there.
If you already have set a page there, go and check under your Pages section in the WordPress dashboard that the page that contains your terms and condition information has the Status: Published.