Erase edges from repeat pattern

[Huda]

Hi, I'm new here so apologies if this has already been addressed. 

Is there a way to erase the edges in a repeat pattern to create a seamless pattern? The below link shows an example of what I mean - it's the white edges that I want erased.

https://topdrawer.aamt.edu.au/var/aamt/s...2_fig2.jpg

Thanks for any help!