it works!

src/main.cpp

@@ -1,5 +1,9 @@
-// The codes that are displayed are not consistent with the GOOGLE Authenticator
-// app.... I guess that TOTP library has an issue...
+// to get the code from Google Authenticator you need to decode base32 and
+// convert that to hex:
+/*
+echo -n "F4ZVI6KKNF4SW5DG" |base32  -d | xxd -ps
+2f3354794a69792b7466
+*/
 
 // I connected SCL to D22 and SDA to D21
 
@@ -23,10 +27,10 @@
 WiFiUDP ntpUDP;
 NTPClient timeClient(ntpUDP);
 
-uint8_t hmacKey[] = {0x62, 0x27, 0x2F, 0x33, 0x54, 0x79, 0x4A,
-                     0x69, 0x79, 0x2B, 0x74, 0x66, 0x27};
+uint8_t hmacKey[] = {0x2F, 0x33, 0x54, 0x79, 0x4A,
+                     0x69, 0x79, 0x2B, 0x74, 0x66};
 
-TOTP totp = TOTP(hmacKey, 12);
+TOTP totp = TOTP(hmacKey, 10);
 char code[7];
 
 unsigned long lastMsg = 0;