our AliExpress access token expires

Hello,

every few weeks I am getting this message:

ALD – AliExpress Dropshipping and Fulfillment for WooCommerce:
Your AliExpress access token expires, products/tracking numbers auto-updating and bulk AliExpress orders no longer work. Get access token

my question is why?
how can I make the token works for 1 year for example?

thanks.