When you give a live long presentation or training in a room for an audience it is normal that you will schedule one or more breaks during you presentation. With a webcast you should do the same.
Arrange for a “coffee / thee” break during your presentation. Use a timer on the screen, so it is clear when you will start again. In live trainings you can easily see when your audience is back on their seats and paying attention again. During a webcast this is more complicated. Having an activity after the break with a polling question / raising digital hand / send messaging can be supportive in ensuring that you have the attention again after a break.
