To use a one-time pad, the sender generates a random key using Generate Key, enters a message and clicks Encrypt, then Package. The URL now contains the message. Copy and paste the URL to the recipient. Transmit the key separately.
The recipient follows the link from the sender, pastes in the key (the Key name can be used to identify which previously agreed-upon key should be used) and clicks Decrypt and can view the message.
Clicking Reply will increment the message offset, so the already-used part of the key is ignored. This way the same one-time pad can be used for multiple messages without having to keep track of what part of the key was used for past messages.
Progressively, the key is used up and then destroyed. Don't reuse any part of the key twice .