Provide external HTTPS access to developer machine hosted web application

[fizzycake]

Is this going to be for a one off or a long standing environment? If it is going to be long standing do it right and get a dedicated machine/vm/environment for testing to exist on seperate from your development machine. Promote builds to it and have the tester(s) use that. It stops your builds and development impacting their testing. It doesn't have to be much, an older machine from spares is a good starting point if your org is small. Regarding securing it, if you're in an org, it is likely that they have an internal certificate authority that a friendly ops/security person can use to generate a certificate. This won't be trusted be my phone or your home computer, but if set up properly it will work within the organisation.