I want to create a lunch ordering bot for my company's department in LINE

I would like to create a LINE bot.

I have already added a LINE official account to our department’s group chat. Our department often orders lunch through the group chat. Everyone typically uses LINE to send plain text messages to place their orders, for example:

Jerry Chicken Bento $160

Then, someone else will copy the previous message and continue ordering, like this:

Jerry Chicken Bento $160
Jackson Pork Bento $160

A third person would continue:

Jerry Chicken Bento $160
Jason Pork Bento $160
Mason Chicken Bento $160

I would like to add a keyword, such as:

Order: Jerry Chicken Bento $160

This way, the bot can automatically tally the orders for me. As long as each person prefixes their order message with “Order:”, the bot will record the message, return the accumulated list of orders, and add the new one to it. So it would look like this:

Colleague A:
Order: Jerry Chicken Bento $160

The bot replies in the group chat:
Jerry Chicken Bento $160

Next, Colleague B:
Order: Jason Pork Bento $160

The bot replies in the group chat:
Jerry Chicken Bento $160
Jason Pork Bento $160

Then, Colleague C:
Order: Mason Chicken Bento $160

The bot replies in the group chat:
Jerry Chicken Bento $160
Jason Pork Bento $160
Mason Chicken Bento $160

Additionally, I need a feature where, when I input “reset”, the bot can reset its memory to avoid recording the previous day’s orders.

I’ve tried using built-in AI and read through many articles but have not been successful. Could you please advise on how I should proceed?