First you must generate a certificate to do so go to resources/pl/edu/agh/dp/tkgk/oauth2server. Then edit ssl_config to include server ip (Change 192.168.55.109 to your local ip). Next run generate_key.sh to generate a certificate. Finally, make your system trust generated certificate (Windows).
If you use Postman, you can the final step and add cert only in postman (File -> Settings -> Certificates -> CA Certificates) [Please use it].
To check if everything is working go to https://server_ip:port/ping, default port = 8080, if cert was added system-wide you can check on browser, if cert was added only in postman use postman.