Plugin sporadicly working or not

I have an issue that i would like to solve, it’s the DHL Parcel for WooCommerce plugin thats used on a big website. Sporadicly and usually after a update the plugin stops working. My assumption is that the use of cloudflare might be the culprit.

If the plugin communicaties with the API of DHL then there is a possibility that the request is being blocked because Cloudflare thinks it’s a bot or none-existing traffic.

What are the IP adresses of this api so that i can whitelist this with Cloudflare?