"How do i" Make a continous backround loop

Im trying to make a auto-runner type game and im having a problem trying to figure out the looping backround events.I have the backround and it starts to go to the right but then when it reaches its other-side it has a gap of white space and puts the symbol back in and i dont know what to put in to fix it.

If you could tell me how to make it loop thatd be great.(Also i opened the template that is "auto-runner" and i was trying to figure it out from there lemme know if its wrong)

Did you check the how do I section ? Check it and call me if you don't find anything ...

No i looked into it it was a giant list of "How do i" section and i found something about terrain being generated but i dont want to do that i just need the tilebackround to loop

...So if ya know what to do i would appreciate it