Pingdom not recognising compression is enabled.

Hello,

I have an issue with the Pingdom site checker
https://tools.pingdom.com/

When checking my site
https://nier.gmlnt.com/

There is the result regarding compression
C78 Compress components with gzip

Compression is enabled on the site but the result is always the same.
Could you let me know how to improve the result on the checker, or more information about the check.
I think Brotli compression is enabled, does the checker check for this? Is there a way to substitute gzip for Brotli for the sake of the check?

Thank you

Paul