Repair information and guides for the minor refresh of the Late 2018 MacBook Air, with the same model number (A1932) and EMC number (3184). This model features a True Tone display and a slightly revised battery.
There is no way that the thermal paste should need to be replaced on a 2019 machine unless something really drastic has happened to the machine. How about telling us what your problem is before you possibly void your warranty.