Hi @Santhosh54 You might need to follow these steps:
1. Click the + Content button that appears on the lecture item
2. Select the type of content you want to add to the lecture. The following steps cover the most common content type on Udemy for lectures, Video.
3. After selecting Video, click Upload to select the appropriate video file from your computer (.mp4, .mov, or .wmv files are supported, and video files should be at least 720p and less than 4.0 GB).
You can also check the following article here for more details.
I hope this helps.
Udemy Community Moderator