From their starting point to your objective
Presentations are amongst the least effective ways of transferring knowledge. What they are good for is changing people’s minds. The panel members might be in a certain state of mind at the beginning of your presentation. This is their starting point. At the end of your presentation and the following interview you want them to be a different group of people. While they might be neutral, maybe hostile or positive, at the beginning, at the end they should be motivated to grant your request for funding. This is your objective. While your audience determines the starting point, you determine the endpoint.
Of course you want to receive the requested grant. However, competition for research money becomes more fierce every year. Rejection does not automatically mean you did not do your job well. There are many things outside your control that do influence the outcome: competition, the state of mind of the panel members, chance. Therefore also formulate a personal goal that is independent of the outcome, but deals with the path towards the interview. It helps you to focus on the things you can control and influence.
When you leave the Webex room, you should have the feeling that you did everything you could. In other words, you have prevented the preventable. This can comfort you when the panel says no, but it also helps you to overcome your nerves beforehand. At the beginning of the interview you can truthfully say to yourself that you are well prepared. Seeing the interview as a matter of life and death makes it more difficult to present in an authentic and truly enthusiastic way, then when you see it an opportunity to expose your ideas to brilliant people.