Answer, do not collect
Most widgets are a form wearing a costume: name, email, "we will get back to you". Nigerian buyers do not wait for that. The agent should answer the actual question, then offer the next step, whether that is a booking, a payment link or a WhatsApp handover.
Know what page they are on
A visitor on your pricing page has a different question from one on your careers page. The widget reads the page and opens with something relevant, which is the difference between a 2% and a 20% engagement rate.
Hand over, never restart
The single most useful button is "continue on WhatsApp". The visitor keeps the thread, you keep their number, and the conversation survives the browser tab being closed.
Look like you, load fast
Colours, avatar, greeting and position match your brand. It loads after your content, so your Core Web Vitals do not suffer, and it degrades quietly if the network is poor instead of hanging your page.