Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. crt.sh | example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
I tried your suggestion but it failed with a message that I did not have the authority. Does it take time for Blogger to know I have contacted Let's Encrypt?
I'm not sure what you mean by that latter part, but opening a thread on this Community doesn't influence anything at the Let's Encrypt side of things: Let's Encrypt is fully automated, nothing manually to be done. So this thread doesn't make any difference.
Further more, I see some "irregularities" with your current setup:
Your hostname resolves to the IP address 72.167.120.230 which is not a Google IP address (Blogger is a Google service), but a GoDaddy IP address;
The IP address 72.167.120.230 is not reachable on port 80 nor port 443, so browsers can't connect to it at all: your site is down.
This describes how to change your DNS records at eNom in order to point your domain to Blogger. (I haven't verified the content myself, but that appears to be what it's explaining how to do.)