He's not - and never has - condemned or opposed it either though; I think the US may have dodged a bullet with not re-electing Trump, because if he used his position as supreme commander to not act on Russia's aggression (which he would be required to due to NATO etc), it would destabilize NATO and make it a toothless tiger. He's always been a fan of Putin, and especially early on during his presidency there were accusations and rumors of him being in Putin's pocket (via extortion, 'kompromat', but given the quotes over the years I don't think that would have been necessary).
Those accusations and rumors were paid for by the DNC [1] and ultimately found to be false [2].
Crimea was invaded under Obama. Russia made no expansionist moves under Trump. The current conflict was started under Biden. Hate Trump all you want, but to say that he would have been worse under these circumstances is a hard argument to swallow.
Reading though the quotes I don't sense a particular affinity for Putin. I just see these quotes as extensions of how Trump likes to talk. He likes to dole out praise, probably thinking it helps his negotiating position by trying to endear the subject to him.
A selection of quotes: https://edition.cnn.com/2016/07/28/politics/donald-trump-vla...