Profile section is at the top right corner. 

Follow these instructions to upload profile picture —

1. Click on the gravater profile or dropdown icon at profile section ( at the top right corner ). 
2. Then click on settings.
3. You'll find upload option.
4. Before uploading profile, you have to compress your profle picture with the dimension of 200px to 500px. Visit Biteable Compressor and upload  your profile picture. Then input the dimension 200px to 500px. ex: height: 500px, width: 500px.  Compress and download your profile. 
5. Then upload your downloaded new compressed profile to rbit. 
6. That's it :)

Thanks a lot for using Rbit —

Kabir from Rbit