Set up generated certificates for each route

I've created two certificates:

$ openssl req -newkey rsa:4096 \
    -nodes -sha256 \
    -keyout whoami1.key \
    -x509 -days 365 \
    -out whoami1.crt
-------------
$ openssl req -newkey rsa:4096 \
    -nodes -sha256 \
    -keyout whoami2.key \
    -x509 -days 365 \
    -out whoami2.crt

These are the subjects:

$ openssl x509 -noout -subject -in whoami1.crt
subject=C = ES, ST = Some-State, O = Internet Widgits Pty Ltd, CN = whoami1.dind.localhost
$ openssl x509 -noout -subject -in whoami1.crt
subject=C = ES, ST = Some-State, O = Internet Widgits Pty Ltd, CN = whoami2.dind.localhost

I've read all documentation about HTTPS and TLS. I don't quite figure out how to set these generated certificates for each route. There are lot of documentation about letsencrypt, but I don't find usefull helping examples about how to use generated certificates. I mean:

route whoami1.dind.localhost uses whoami1.crt
route whoami2.dind.localhost uses whoami2.crt

Any ideas, please?