AnyChat

I recently purchased a few tools on the AppSumo Black Friday Sale. Had to return 2 tools as they didnt serve me much but AnyChat is a big win.
They not only offer chatbot widget but the whole Help Center with tickets management, Knowledge base, and the cherry on top "White Label".
There is a learning curve but as you set your account up you will fall in love with AnyChat.
There are still some improvements to be done, but if you are reading this, don't waste time, AnyChat is one of those tools to have. 100% Recommended