The intention behind having an SSL/TLS certificate was not just for authentication but also to establish the identity of the remote server with whom the client browser communicates.
SSL /TLS protocol to ensure that data travels securely over the wire. Encrypting data in transit helps to prevent any malicious user from sniffing the network to steal sensitive information like passwords, credit card details, etc.
SSL or Secure Sockets Layer and TLS (Transport Layer Security) are cryptographic protocols designed to provide a secure communication channel between clients and servers over the internet. TLS is the relatively newer version when compared to SSL, SSL is the older encryption protocol.
Install a free SSL certificate all by yourself (The certificates are provided by Let’s Encrypt®, a non-profit Global Certificate Authority). The link is as below