Is there a way to embed on a list item? Like storing the link in a list rich text column and when the item is opened, it will display the map?
Are you using modern lists? An alternative to embedding an iframe could be to use View Formatting. View formatting simply uses JSON and can really improve the design of a SharePoint list.
A good example with Google Maps integrated can be found here: https://github.com/SharePoint/sp-dev-list-formatting/tree/master/view-samples/contact-card-format
Not in SharePoint Online Calculated Columns. They removed the "bug" that we used to use for this.
You should still be able to get there using a workflow, but it may not work on Modern UI pages.
We can add the code below into script editor web part into the DispForm.aspx page to achieve it.