Say you want to only show Store Pickup when certain items are in the cart. For example, large furniture or items that aren’t shippable. They need to make sure that In-Store Pickup is already set up, if not click here to set that up.
You must create a Shipping Group for the products that are going to be In-Store Pickup only.
In the Shipping Group settings, under the Optional panel, under the Restrict to Specific Shipping Methods section, Add In-Store Pickup under Custom Shipping Methods Assigned.