I want a simple dropdown for locations in woocommerce

I want to have multi locations for pickup. I want it no where in site, only in checkout when someone click pickup at local pickup, then this dropdown appear. And also it go in emails etc and so on.

I tried plugins but none of plugin work like this. One work and they are not fixing bug.

Is there any way that I just put the list or custom post type in backed for the list of local pickups, and as soon as person click on local pickup, then the list appear in dropdown just next to it.

Please help

Thanks a lot in advance...