How to enable SSL for website AND traccar?

Of course, Anton.
I tried to follow the instructions here: https://httpd.apache.org/docs/trunk/vhosts/examples.html

Listen 443
Listen 8082
 
<IfModule mod_ssl.c>
<VirtualHost *:443>
    ServerAdmin webmaster@localhost
    ServerName mysite.info
    ServerAlias www.mysite.info
    DocumentRoot /var/www/montinaro
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined
 
Include /etc/letsencrypt/options-ssl-apache.conf
SSLCertificateFile /etc/letsencrypt/live/mysite.info/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/mysite.info/privkey.pem
</VirtualHost>
 
<VirtualHost *:8082>
    ServerAdmin webmaster@localhost
    ServerName mysite.info
    ServerAlias www.mysite.info
    DocumentRoot /var/www/html
 
    ProxyPass /api/socket ws://localhost:8082/api/socket
    ProxyPassReverse /api/socket ws://localhost:8082/api/socket
 
    ProxyPass / http://localhost:8082/
    ProxyPassReverse / http://localhost:8082/
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined
 
Include /etc/letsencrypt/options-ssl-apache.conf
SSLCertificateFile /etc/letsencrypt/live/mysite.info/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/mysite.info/privkey.pem
</VirtualHost>
</IfModule>

Sorry but I think I'm not so good with Markdown.

@Track-trace
I've not used Proxypass because I'm not able to configure it.
What you saw before is, as stated, the current configuration of conf file

Regards,
Piero

Obviously this won't even start because you're trying to use the same port for Apache and Traccar. You either need to pick a new port in Apache or change port in Traccar.

You are right. That was the first problem.
I've noticed that If I remove the first two lines:
Listen 443
Listen 8082

Apache starts, but the situation is the same.

I repeat, I did a lot of attempts, but I have no experience with Apache webserver, sadly.