All webSDK license keys work on localhost independently of the particular domain name for which the license was created.
Additionally, all private IP ranges are supported as listed here:
https://en.wikipedia.org/wiki/Private_network
In other words, any webSDK license key should work both on the specified domain as well as on localhost.
In case there is a problem with license validation, the logs will show a license error indicating the exact cause of the issue.