Hey! Thanks for reaching out! for online, I recommend rolling a d20 each time you'd pull a block, noting the number each time. If you roll the same number 3 times, count that as the tower falling. Unfortunately I don't know where you'd find an online tarot deck to pull cards from
I consider the tower falling the end of the game, but if you wanted to, you could restack it. I'm not the boss of you. :D
when I played with a friend online, we used https://randomtarotcard.com/ , and to simulate the jenga tower we started with 100d6 and every time we would 'pull a block', we would roll the entire dice pool and remove all 1s, with the fall condition being no dice left. (ie, the first time we rolled/pulled a block, we had 9 1s, so then we were rolling 91 the 2nd time, etc). the balance of how likely you want the tower to fall can be adjusted with number of starting dice-- I think we ended with 8 dice left in the pool, so we got down to the wire, but we were never in a "1d6 left don't roll a 1" situation. I think 80-100 starting dice will get you to a high-risk level at the end without guaranteeing a fall.
I used this https://tarotpoint.com/random-tarot-card-reader to get a random tarot card when I played this.
