[API] Invalid API key or access token (unrecognized login or wrong password)

Hi,

Today I bought your app: import Shopify to WooCommerce application.
I got the API and password from Shopify and I pasted it into your application in WordPress.

The problem is that when I am saving, I get the following error: [API] Invalid API key or access token (unrecognized login or wrong password).

What should I do, please?

Thanks in advance.

Best regards,

Alejandro