@vi8a this is totally normal, because you are using a selfsigned certificate.
Your browser does not trust this certificate or the one who issued it (CA = Certificate Authority).
You have 2 ways to go:
- you choose "Aceptar el riesgo y continuar" (because you know the one who made the cert)
- or you use a certificate from a trusted issuer (like, LetsEncrypt or other official CAs)
There would be a third one but we don't go into that now ;o)
Please read this https://en.wikipedia.org/wiki/Public_key_infrastructure and you will gain information about certificates and public key infrastructure.