The expiration was not determined

[Stratis]

For years i have in my .htacces file this:

<IfModule mod_expires.c>
ExpiresActive on
ExpiresByType image/jpg "access plus 7 days"
ExpiresByType image/gif "access plus 7 days"
ExpiresByType image/jpeg "access plus 7 days"
ExpiresByType image/png "access plus 7 days"
</IfModule>

It seems that does not take effect. Do I must change the path?
Something like this? (see first post for others)

ExpiresByType customavatars/avatarxxx.gif "access plus 7 days"

Thank you for answering, I appreciate it