fix(publicip/api/cloudflare): add Referer header (#3058)

internal/publicip/api/cloudflare.go

@@ -40,7 +40,8 @@ func (c *cloudflare) Token() (token string) {
 func (c *cloudflare) FetchInfo(ctx context.Context, ip netip.Addr) (
 	result models.PublicIP, err error,
 ) {
-	url := "https://speed.cloudflare.com/meta"
+	urlBase := "https://speed.cloudflare.com"
+	url := urlBase + "/meta"
 	if ip.IsValid() {
 		return result, fmt.Errorf("%w: cloudflare cannot provide information on the arbitrary IP address %s",
 			ErrServiceLimited, ip)
@@ -50,6 +51,7 @@ func (c *cloudflare) FetchInfo(ctx context.Context, ip netip.Addr) (
 	if err != nil {
 		return result, err
 	}
+	request.Header.Add("Referer", urlBase) // returns HTTP 403 otherwise
 
 	response, err := c.client.Do(request)
 	if err != nil {