Before the following steps, please create folder c:/nginx/html/.well-known first with mkdir c:\nginx\html\.well-known.
C:\nginx>C:\win-acme\wacs.exe
Error creating event logger: The source was not found, but some or all event logs could not be searched. Inaccessible logs: Security.
A simple Windows ACMEv2 client (WACS)
Software version 2.1.6.773 (RELEASE, PLUGGABLE)
ACME server https://acme-v02.api.letsencrypt.org/
IIS not detected