Adds note about File Sandboxing

Author: angelampcosta

src/content/docs/data-localization/compatibility.mdx

@@ -148,7 +148,7 @@ The table below provides a summary of the Data Localization Suite product's beha
 
 [^20]: You can [bring your own certificate](https://blog.cloudflare.com/bring-your-certificates-cloudflare-gateway/) to Gateway but these cannot yet be restricted to a specific region.
 
-[^21]: Gateway HTTP supports Regional Services. Gateway DNS does not yet support regionalization. <br/> ICMP proxy and WARP-to-WARP proxy are not available to Regional Services users.
+[^21]: Gateway HTTP supports Regional Services. Gateway DNS does not yet support regionalization. <br/> ICMP proxy and WARP-to-WARP proxy are not available to Regional Services users. [File Sandboxing](/cloudflare-one/policies/gateway/http-policies/file-sandboxing/) (add-on) is incompatible with DLS.
 
 [^22]: Dashboard Analytics and Logs are empty when using CMB outside the US region. Use Logpush instead.