No. The adapter is very odd to me and the instructions took some interpretation.
Basically for the adapter to work you will have to get to the air handler. And the air handler needs to have a power source for the “c” wire. (My unit for exaplme doesn’t use a board with marked “r,c,w,g,y” terminals. And I found it much easier to just install a new thermostat wire with 5 leads). The adapter allows you to use your existing 4 wire thermostat wiring, it just changes how they are used to make sure the thermostat itself has power.