To do so just click on the video button next to the person’s name.
While the battle between the chatting softwares are becoming more and more each day so providing the users with video chatting option is essential to gain the market.
The old & almighty skype is already there for the voice and video calling for a long time but the new players like line, imo are trying to get on the market.
While whatsapp and wechat is now the current leading texting platform but they do not offer direct video calling, well, you can send a video messages but you can not directly call your friend like you can do in skype or line & now in imo.
So just wait for the update and it will be live on google play & apple app store.
If you don’t have imo then you can download it here.