Contents of a civil recovery letter?

So I will shamefully admit it was the first time I shoplifted today, and I was caught, which is completely fair.
To add context what I stole was £1 of course- doesn't justify it.
What I am here to ask is what is the contents/ basic structure of a civil recovery letter. The manager did mention the minimal fine was £103, however, some have told me that was purely a means of intimidation.
I would like to add I do fully intend to pay the fine no matter the costs, and just wanted to know the structure of the letter and what it contains

So, TLDR; whats the structure of a civil recovery letter?

If you're nicking stuff that costs a pound you've immensely failed at life.