How To Set Up HTTPS for eero DDNS.

I have DDNS set up and can access my computer/services from outside my network, however only over HTTP. This article says it is possible to set up HTTPS using Let’s Enrcypt but stops short of explaining how. The link to Let’s Encrypt is equally unhelpful. 

Has anyone successfully set up HTTPS on the domain provided by eero for DDNS, or found useful instructions on how to do so? I’ve not found anything helpful on the web. Thanks in advance!