How to add a comment to an order?

Question

opencart

DD!
Please tell me how can I add the ability to leave a comment when placing an order?
Now, with the help of refinement, ordering takes place in 1 step, just confirmation of the order and that's it, as intended.
I know that in the standard functionality there is an opportunity to leave a comment on the delivery step. But I do not have this step and will not.

Answer 1

See how it is implemented in the standard functionality and copy it for yourself. It is strange to read such a question from a person who has mastered placing an order in 1 step.