There are many apps that can sync inventory for various reasons.
One https://usemechanic.com allows scripting for more complicated situations.
They even have a library of premade scripts including for inventory sync'ing
If you need such custom solution I can be contacted at email@example.com
Hello, after searching multiple forums thought I share an easy solution for multiple pickup locations without an app, or installing code or using multiple location inventory tracking.
Inside Shopify > Products > Scroll to Quantity > Choose Edit Locations and from here you can select the locations that will display on checkout.
You have to do this for every product but still a good workaround. Hope this helps.