Can I use the CronJobs plugin to renew the SSL certificates generated by the LetsEncrypt plugin?
If yes, could you give me an example for this?
Does it work per user/domain or will it renew all certs at once?
Of course if yes, I will buy the plugin 
Examples are important for me please.
Hello, please took the Forum search. This question is already answered.
The letsencrypt plugin is already renewing the certificates automatically.
i did use the search funtion thats why i ask the search results are way to confusing and not clear.
@ Ninos so you say i dont have to do anything just install and activate and then its all auto update
and i dont need the cronjob plugin for this
The renewal feature doesn't require another plugin 
The cronjob plugin allows clients to make custom cronjobs.
The LetsEncrypt plugin comes with a cron job that is responsible for SSL certificate renewal (by default, SSL certificates are renewed one month before their expiration). The SSL certificates are only renewed when needed. Once you activate LetsEncrypt for a particular domain, you have nothing more to do. All is done automatically, including renewals.
The CronJobs plugin allows the administrators and the customers to add cron jobs through the control panel. That plugin is not required by the LetsEncrypt plugin. The LetsEncrypt plugin registers its cronjobs using i-MSCP core API.
I hope that I'm clear enough.