Sometimes OSM displays "Referer is required"

[AlainR]

Hi.
I set up a new site and since 3 or 4 days, I am sometimes confronted with a problem of displaying the tiles of the Openstreetmap map with the message "Referer is required" and a reference to the https://wiki.openstreetmap.org/wiki/Blocked-tiles
This one indicates that I have to configure Referrer-Policy header to any of no-referrer-when-downgrade, origin, origin-when-cross-origin, strict-origin, or strict-origin-when-cross-origin.

My question is: is it at the Phoca Maps component level or elsewhere in the site that I have to do this?