PayPal Express Checkout Image – Not HTTPS

Been working through removing and addressing all mixed content on my checkout page. The PayPal Express Checkout image on my checkout page is the last item on my list.
https://i205.photobucket.com/albums/bb145/matstone7/Capture_zps5c70fe0e.png

I get a Mixed Content Error
Mixed Content: The page at 'https://xxxx/checkout/' was loaded over HTTPS, but requested an insecure image 'https://xxxx/wp-content/plugins/paypal-for-woocommerce/assets/images/paypal.png'. This content should also be served over HTTPS.

The button makes a call to http not https, Can you direct me to where and how to correct this please?

Thanks in advance

https://www.ads-software.com/plugins/paypal-for-woocommerce/