Question / Help Minecraft black side bars please help

[killzoz123]

trying to record some minecraft with OBS is there away to improve the screen like to full then little side bars?

 

[killzoz123]

Here is the video of showing the black bars.
https://www.youtube.com/watch?v=dggzLCcDYfQ&feature=youtu.be

 

[Harold]

Video removed by user