Sorry I forgot there were two separate furnaces being discussed!
Kidkraz- Even if the thermostat clicks it can still be bad, especially if it’s the original mechanical tstat. Disconnect the two wires at the tstat and twist them together. Does the furnace start and run? Bad thermostat. I’d replace it with a simple non-programmable heat-only tstat.
https://a.co/d/34UF2FB
https://a.co/d/08U2bWz