Social warfare sharing

I am using social warfare, and apparently their social share images can’t be cached. they have an article how to fix it in other popular caching plugins
9https://warfareplugins.com/support/my-icons-are-showing-letters-instead-of-the-proper-social-icons/), but I can’t translate them to fastest cache. Could you help me know what to fix?

Thank you!

https://www.ads-software.com/plugins/wp-fastest-cache/