How Letsencrypt renewal works?

Hi,

When I add Letsencrypt to a domain and set it to auto renew every 2 months, when the 2 months is over, if for some reason the renewal fails, then how frequent does Virtualmin try to renew again? Is it every 5 minutes?

Let's say, if SSL of my domain expired for some reasons, and I want to manually ask Virtualmin to retry it (so that it processes immediately), is that possible?

I'd like to see a button, when we click on it, it will attempt to try to add/renew SSL for the specified domain, is there such things in virtualmin?

Thank you very much!