Need to create video with an image and audio

I Need to create video with an image and audio, please guide.

Import Image into playlist.
Drag it into a video track on the timeline.
Import audio into playlist. Create an audio track, drag it into Audio track on the timeline. Adjust image track length to match.

Did this then I try to export to mp4 but it failed.

Okay done, but the problem is that I drage image to adjust the length but it stops at a limit, however my audio is big, I want the image to completely come over the audio.

Just drag another copy of the same image from the playlist to the end of the same track.