API limitations

[Bacto]

Hi,

I have tried to use the API to check regularly some destinations over the world and ensure there is no routing issue.
On the paper, mtr.sh API is the best for that (btw, thank you for mtr.sh, it is really an awesome tool!).

Unfortunately, after few requests, it seems that my IP is blocked (probably dropped on a firewall?).
What are the limitations and how can I avoid to be blocked like this?

Thanks,
Adrien