Just use the commenting syntax within a comment.

+++1 XLM
+++1.4123 XLM
+++2.4123 xlm
+++1.21xlm
+++ 1 xlm

The XLM will be credited to the reddit account to which you replied. That's all.

In order to tip with the bot you need to deposit stellar lumens (XLM). Send any amount of XLM to:

GCQKBTYJHWSTHQWIKIQYAORZGHPSF2WXGNUYXO6A2VGKGSYUZNA2Y4E4

In the memo, put:reddit/your-user-name

The memo is important in order to deposit. Be sure to always send a memo and use your own username. You will receive a private mail once the XLM is deposited.

Click here and change 'Amount' in the first line to the amount you want to withdraw and change 'address here' to your public key.

Hit send. You'll receive a message once the transaction is send. Important: This bot will never ask you for your secret key.

Click here & hit send. You'll receive a message with your current balance.