the git repo is over 5 years old. sounds like it’s outdated?
I would prefer a better, fresher way to switch the location to dropdown. Generally a drop down is the better choice for this field anyway, because you can select existing cities/regions there. So the user does not run the risk of not getting a result.
While it’s certainly true that a more up to date resource would be desirable, this functionality is not currently possible in default WPJM, so it will require custom code. We aren’t able to help with custom code requests like this, so if you need assistance, you may want to look into one of these services: