Ah!
I found this in coolwsd.xml and disabled ssl and enabled termination:
<ssl desc="SSL settings">
<!-- switches from https:// + wss:// to http:// + ws:// -->
<enable type="bool" desc="Controls whether SSL encryption between coolwsd and the network is enabled (do not disable for production deployment). If default is false, must first be compiled with SSL support to enable." default="true">false</enable>
<!-- SSL off-load can be done in a proxy, if so disable SSL, and enable termination below in production -->
<termination desc="Connection via proxy where coolwsd acts as working via https, but actually uses http." type="bool" default="true">true</termination>
Now itโs running!