You need to compile ngrok with a self-signed certificate.
To use Let's Encrypt's free certificate, you need to execute the following command to replace the certificate file in the source code:
Note: Please replace "ccce.top" with your own domain name.
client certificate
cp /etc/letsencrypt/live/ccce.top/chain.pem assets/client/tls/ngrokroot.crt
Server-side certificate
cp /etc/letsencrypt/live/ccce.top/cert.pem assets/server/tls/snakeoil.crt cp /etc/letsencrypt/live/ccce.top/privkey.pem assets/server/tls/snakeoil.key