The Bigblue Pickup point selector is compatible with all Shopify plans. The difference between Plus and non-Plus plans is the availability of Checkout Extensibility (source), which enables you to add the pickup point selector to your checkout.
If you don’t have access to Checkout extensibility, the pickup point selector will appear on the Order Thank You and Order Status pages.
If this error appears when loading the Map, it may be that the Google Maps Javascript API Key is not properly setup. To know what is wrong, open your browser’s developer console and look for a message like this:
<aside>
💡 ExpiredKeyMapError
can be displayed for a few minutes if you’ve just created or updated your API key. We suggest retrying after 5-10 minutes.
</aside>
<aside>
💡 RefererNotAllowedMapError
means the Google Maps Javascript API key you supplied was configured with the wrong website restrictions. See Google Maps Setup.
</aside>
For other errors, consult Google’s error documentation:
Error Messages | Maps JavaScript API | Google for Developers
If this error appears when loading the Map, it may be that the Google Maps restricted your access to. You need to check that you added your bank details on Google maps and that your API keys are correctly setup. (see section Google Maps setup).