Trying to solve this also. Same problem here. Where can I find Apache2 config in snap? I have read the link Collabora - Built in Code - Reverse Proxy / "ssl.enable" and "ssl.termination" - #2 by wwe
But not where you van edit this… Please help 
hi @webthingz welcome to the forum 
I doubt you your issue is the same as in two-year old topic, for this reason I split into separate thread. Please provide additional information and logs as requested in support template
usually you don’t need to mess with ssl.enable for built-in code as all request flow through the richdocuments proxy. If there are specific issues or error please describe what you tried so far and which problems you hit!