This is an old fashioned methodology designed for the days when travelling to the client was expensive and the only pre-work you could do was a brochure. Think again.
They always say that the best work in a meeting is done outside the room. The meeting itself is only where you ratify the deals done elsewhere. Adopt this as your strategy. And use the modern methods.
You have multiple people at your client, all with different needs, concerns and goals. Identify them. Use the forthcoming meeting as a chance to find out what each one wants from the meeting, and from your product. Send them links, useful background reading, ideas etc. and get their feedback to agree what it can do for them. Get them on side as your evangelist in the meeting.
Pre-send the demo - which should include a video, an interactive "you do this, then this" and an FAQ list. Encourage them to add their own questions in advance - promise you will answer at the meeting. Who cares how the website works - if it matters it should have been well enough designed that how it works is obvious.
People buy "people like them". Way beyond the facts, they want to see how this stuff plays out in real life. So show them how it works in practice with real clients - if you haven't got any, then show them your customer research, your target sectors and Use cases for each.
Work out some financials too - how do clients get ROI, how quickly and how safely.
Then minimise risk - show why it is a safe option.
Cover competitors. Don't pretend they don't exist. Create a tickbox chart, a financial costs and returns, a problems solved comparison and a Gartner segment (it doesn't actually have to be from Gartner).
All in advance.
Now when you get to the meeting it can be all about action. What are the next steps, how do we work together. Build momentum up to the commitment.
Now this is the client strategy.
For investors, there is one addition. What's in it for them. Show how the deal progresses - seed to A to B. Show how they make returns at each stage. Justify your valuation. Make your equity for cash pitch. And show them the team, progression planning, resilience built in (what happens if someone leaves).