Even if you are alone you can add this easily. Especially for an expensive or complex product live chat can mean the difference between a sale or an abandonded card. There are a lot of tools out there. I use https://small.chat/ to connect the live chat to my development slack channel.

Take a look also at:
https://www.intercom.com/
https://retainly.co/chatterbox
https://www.talkus.io/
et.al.