Tested successfully on Ubuntu 20:
snap install core; sudo snap refresh core
snap install --classic certbot
tpeap stop
certbot certonly --standalone --preferred-challenges http -d example.com
openssl pkcs12 -export -inkey /etc/letsencrypt/live/example.com/privkey.pem -in /etc/letsencrypt/live/example.com/fullchain.pem -certfile /etc/letsencrypt/live/example.com/chain.pem -name eap -out omada.p12 -password pass:tplink
cp /etc/letsencrypt/live/example.com/fullchain.pem /opt/tplink/EAPController/data/keystore/eap.cer
keytool -importkeystore -deststorepass tplink -destkeystore /opt/tplink/EAPController/data/keystore/eap.keystore -srckeystore omada.p12 -srcstoretype PKCS12 -srcstorepass tplink
tpeap start
How To Install LetsEncrypt SSL Certificates On Omada Controller
Thank you for posting this! I spent hours yesterday trying to fix my certs, and after finding this today, sorted it out in less than 5 minutes. Works on Ubuntu 22.04. I followed from
tpeap stoptotpeap startand now my browser warning is gone.