The winner is fully determined by the block hash above — fixed and public the moment that block was mined.
142 tickets were issued, numbered #69420–#69598 with small gaps (a few comped/test orders were voided before the draw — every remaining ticket, paid or free, was equally eligible).
The winner is the (sha256(block_hash) mod 142)-th ticket in the sorted list of issued tickets:
winner = sorted(tickets)[ int(sha256(block_hash), 16) mod 142 ]
= #69521
Reproduce it yourself — this pulls the published ticket list and indexes into it:
python3 -c "import hashlib,json,urllib.request as u; t=sorted(json.load(u.urlopen('https://21raffle.com/result/tickets.json'))['tickets']); print('#'+str(t[int(hashlib.sha256('00000000000000000000b781d6fa58a027cbf0be55ff4e9ea1efd66402e81526'.encode()).hexdigest(),16)%len(t)]))"