I beleive the limit is five failures within an hour.
Looking at: Rate Limits - Let's Encrypt (letsencrypt.org)
I don't see that specific error message explained in detail.
"There were too many requests of a given type"
You'll likely have to wait until there are only four within the last hour to try again.
But repeating the same request, without making any change(s), will only produce the same result.
You should use the staging environment to do as much testing as you need [and until it passes those tests].