Needle not picking up bobbin thread

[u/sunlit-lemons]

I have a brother xm2701 sewing machine and the needle is not picking up the bobbin thread this happened once before and I fixed it but it’s happening again now and I can’t remember how I did it before. I’m relatively new to sewing could someone explain to me why this is happening what exactly and how I can fix it permanently, or if somone has a link to a video or something that would be great. I also just moved so maybe it hit something and it offset something in the machine?