Without knowing what you want to do with that post or why you need it, it’s a little difficult to suggest something helpful for you.
Do you simply want to know about posts being marked as the solution?
Then you could use a data explorer query and the “Schedule a post in a topic with Data Explorer results” script. You could, for example, run a query that returns the solutions from the past 10 minutes every 10 minutes.
I guess you could also run it more often, but I am unsure how much this adds on the server. But even if you ran it every minute, you wouldn’t necessarily get a post for each solution. Maybe there are 2 topics solved within the minute.
Furthermore, the resulting post can only be customized to a limited extent. (Of course, you can customize the texts used like any other text, but you should bear in mind that you will then have to do this for every post that is changed by automation with this script. So it doesn’t really work if you want to be too individual.)
Simple example of a post created by that automation:
The content of the table depends on the query. It is possible to expand the query, for example, to display a link to the topic or the solution. I kept it simple for demonstrating how the feature generally works.
The query I used
SELECT
dst.created_at AS solution_accepted_at,
dst.topic_id,
dst.answer_post_id,
dst.accepter_user_id
FROM discourse_solved_solved_topics dst
WHERE dst.created_at >= NOW() - INTERVAL '10 minutes'
ORDER BY dst.created_at DESC