Problem with shortcode

Hello
I am a new user and i can’t use the shortcode apcal. Is here someone, who can show me how to use short code step by step?. I’m using theme Spacious. I can find the shortcode in fil “appointment-calendar-shortcode.php” but when i paste all content it doesn’t work. On my website i see all content of shortcode.
Thanks for attention

https://ww.wp.xz.cn/plugins/appointment-calendar/