A test authorization for router.jpleva.cz to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
164.215.116.174: Fetching http://router.jpleva.cz/.well-known/acme-challenge/MnqQaYIpg0drZFDujqLU_ww1CTGTYHzClIGnfnoqIhg: Timeout during connect (likely firewall problem)