Take two consecutive messages you got from Moirai (directed at you).
Find their "index" by entering the messages on the left side and finding the understandable line.
The difference between the indexes is your "shift-rate".
E.g. if the first message is at 13 and the next message is at 23 your shift-rate is 10.
You can use a negative shift-rate if you want if the messages are closer that way.
Talk with the bot:
Enter the last message from Moirai to you on the left side.
Find the line that makes sense.
Enter your message on the right side.
Choose the line that is one shift-rate away from Moirai's line.
E.g. if the understandable line is at 6 and your shift-rate is 10, you have to pick your answer from line 16.
If you reach the end of the list just continue counting from top (87 + 10 = 3)
You can also set your shift-rate in the settings. That way messages will always be one index apart.
So if you set your shift-rate to 10 and Moirai's message comes in at 17, you can answer with 18.