unable to activate browser caching

Hello, I just installed the hummingbird plugin and it says that I am unable to activate browser caching.This is what the error message says:
Browser Caching is not working properly:

– Your server may not have the “expires” module enabled (mod_expires for Apache, ngx_http_headers_module for NGINX)
– Another plugin may be interfering with the configuration
If re-checking and restarting does not resolve, please check with your host or open a support ticket with us.

could someone please have a look? thank you

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