Shoutbox

There isn't something to auto-accept because the very same effect can be achieved by turning this option off:
    Tools > Options > Privacy > Only people on my Allow List can see my status and send me messages
And then you can disable:
    Alert me when other people add me to their contact list.


This makes that anybody can add you and start talking to you without you receiving a request popup.
Which has the same effect as auto-accepting everything.

However, as Chris4 rightfully noted: This is a security risk!
You really should not be auto-accepting contacts these days!
So, I strongly encourage to keep that option on and to manually click on the popups.

They are indeed there for your own privacy and safety.
And normally you shouldn't be recieving constant requests from new contacts either.
If you do, they are probably spambots anyways.