I was filling up-amounts of gas were leaking onto the ground?

It sounds like this line that you have a crack in is part of the filler neck which is actually a vent line or EVAP emissions line.

If that is the case, then we need to replace the filler neck.

I will attach the info below on how to do this.

You may need to lift the truck so here is a guide that will help with this:

https://www.2carpros.com/articles/jack-up-and-lift-your-car-safely

Please see the attached info below on how to replace the filler neck which should come with this line attached to it.

Let us know what questions you have on this. Thanks