Hi @Spartacus2018,
For configuring SSL, you have two options:
- Set up TLS on Mattermost Server.
- Install a proxy such as NGINX and set up TLS on the proxy.
More details here: https://docs.mattermost.com/install/config-tls-mattermost.html.
If this doesn’t help, can you help share a link to the installation guide you followed and I can take a closer look.