A lot of 4 in that numbers string which should guide you on the split. That “d” is a hint that tells you where to start from

D is a hint for roman numeral 500. There are a lot of 4 in that string and if you look closely you’ll notice that every third number is a 4. Make groups of 3

417 415 433 444 443 449 449 443 419 415

From 500 subtract each numbers

83 85 67 56 57 51 51 57 81 85

We now have a good Ascii range, convert decimal to Ascii

SUC89339QU

Now we need the keyword, the operation we used to get those numbers was 500 LESS the numbers

suc89less339qu

Code #2

Observations

Numbers separated by letters. Maybe 2 passcodes ? 3 is the best hint for this code

Let’s start by isolating the numbers that the letters are splitting