They were using a lot of their Kalibr missiles to strike Kiev and there were reports that in the first half of 2022 they had less than 100 of them left.
Since there were many launches since then and we even have videos of Ukrainians shooting down Kalibr missiles with MANPADS, we can safely say that Russians are running low.
As for the lies, there are intelligence unts assigned to watching and counting every single piece of armor, every ship and plane. Do you really think that NATO forces didn't have spies in Russia long before the war in Ukraine? Both sides know a lot about their armaments and what the Ukrainians didn't know they got from hundreds of Russian PoWs.
If Russia was doing good supply-wise its soldiers wouldn't be running with Mosins and using armor plates made of road signs.