cache policy (TTL)

Hello,

I need to serve static assets with an efficient cache policy, however these js files are from a cdn video provider which don’t have a cache TTL

https://shottr.cc/s/0AxT/SCR-20220327-tsg.png

I added to .htaccess the following cache-control headers

https://shottr.cc/s/0TLK/SCR-20220327-v2v.png

However when I run GTmetrix I still get the same warning ¿how do I add cache TTL to these js files?

Thank you!