I have found a quite a few references to LE behind proxy, but I could not apply the comment to my case. Sorry, I am Reverse Proxy Challenged.
The question is a followup to a comment I wrote on the German Forum of ISPCONFIG
Apache 2 on Ubuntu. Let’s encrypt works perfectly and updates without problems on all non-proxied sites. However, I have some sites that need a reverse proxy to run Rstudio Shiny. Example Breath Test Shiny.
LE works, but automatic renewal fails. To force renewal, I have to remove the proxy first, and the re-insert it. Till on the ISPCONFIG forum suggested to add LE to the passed part, but I don’t understand which path to insert to let it pass.
<Proxy *> Order deny,allow Allow from all </Proxy> ProxyRequests Off ProxyPass /stats ! RedirectMatch permanent ^/apps/$ /apps/ ProxyPreserveHost Off ProxyPassMatch ^/(.+)/websocket ws://localhost:3838/$1/websocket keepalive=On ProxyPass / http://localhost:3838/ ProxyPassReverse / http://localhost:3838/