As far as I am aware there is unfortunately as yet no mechanism within Airbnb to apply this tax within the system to cover the criteria - namely a 5% levy of the total guest accommodation cost, to be applied only for stays from 24th July 2026 onwards (when the Visitor Levy starts in Edinburgh), and only for the first 5 nights of any stay.
Sorry not to be able to help. Edinburgh hosts would doubtless find it helpful to know from Airbnb if a tool is planned to be introduced to help them with this if they plan to pass on the tax to guests, as all charges have to be visible to guests at the point of booking under UK consumer law. I believe I heard in the past that a mechanism may potentially be made available, but not until the 24th July start date.