Can I refuse to get a product from another location for my assistant manager?
What makes you not want to get a product from another location?
I don't feel like making the extra effort.
Most job descriptions form part of your contract of employment and include a clause stating that you can be asked to undertake reasonable tasks outside the scope of the work specifically described. You can be fired for declining to do something that is not in your job description.
I think I'm going to call my manager and tell him I don't want to.
You're allowed to do that, but know that by refusing to do what he asks, that you're risking your job. The task he's asking you to do seems reasonable, so I think you should just do it.