First, go to Themes page in Shopify Admin Panel. Select the Customize button.
The Store Locator feature can only be used in pages that are categorized in Pages. For this example we will be selecting the Pages > Contact at the page navigator located at the middle of the screen:
Next, select + Add section at the sidebar and proceed to select Store Locator located under apps (it might take a few seconds for it to load).
Once Store Locator app is added, locate the button app block and click and drag it to the desired location.
Select Save to complete this process: