Caddy Server - getting error for local domain - "Certificate is not valid"

Question

I have installed caddy with the following docker compose so that I can use it as a reverse proxy for one of my wordpress installation.

services:
  caddy:
    image: caddy:2.6.4-alpine
    container_name: caddy
    ports:
      - 80:80
      - 443:443
    volumes:
      - /mnt/wp1:/var/www/html
      - /mnt/caddy/caddy_data:/data
      - /mnt/caddy/caddy_config:/config
      - /mnt/caddy/Caddyfile:/etc/caddy/Caddyfile
    environment:
        ACME_AGREE: 'true'
    restart: always

Here is my Caddyfile.

raspberry2.local {
    reverse_proxy 192.168.142.135:8982
    file_server
    tls internal
}

**Issue - Getting "Not Secure", "Certificate is not valid" error. Please check the following screenshot. **

Error Screenshot

How to resolve this issue?

I tried making necessary changes in the Caddyfile but still getting "Not Secure", "Certificate is not valid" error.