Visitor picks a day and time from the firm's hours. The request opens their email app addressed to the firm — no backend, no calendar account needed.
<script src="https://widgets.legelocity.com/booking/legelocity-booking.js" data-firm="Jane Doe Law" data-email="book@janedoe.law" data-days="1,2,3,4,5" data-start="9" data-end="17" data-slot="30"></script>
Buyer sets open weekdays (0=Sun…6=Sat), hours and slot length. That is the whole setup.