How to add a dialog box to your recorded video file?

You need to use a video editing software. Let me take this software commonly used by ordinary people as an example.

First, open the love editing software, and click to start making videos.

After entering the video production page, find the node you want to join the dialog box from the bottom of the imported video, click in, and then select Add Material, as shown in the figure below.

Select Add Map and the following screen will pop up. Just select the dialog box. After adding a dialog box, you can move the position freely on the right. After the position is fixed, double-click the dialog box and fill in the desired text.

Remember to adjust the time after filling in the text, and then you can check the effect of joining the dialog box by yourself, and then adjust it if you are not satisfied.