This is complicated. For context, there's a 1936 international treaty that regulates traversal of the Bosporus Straits called the Montreux convention [1]. it generally allows the passage of warships with a couple of exceptions and it depends on if Turkey is at war or not.
What happened in 2022 is that Turkey decided Russia's invasion was a "war" (in the context of a treaty) and thus limited access to the Black Sea to Russian warships. But that comes with a couple of restrictions.
The most notable one is that Russia is allowed to use the passage for ships based in the Black Sea and that was important. Ukraine could (and did) attack ships in Sevastopol and when that happened, they would have to retreat to repair (if possible). And they went to Syria to do that one several occasions.
Turkey's relationship with Europe, NATO, the US and Russia is... complicated. Like Turkey is the largest military in NATO (other than the US of course) and does pretty much whatever the US tells them to, but they also buy Russian armaments (eg missile systems) and the US has stationed nuclear weapons in Turkey. And while buying Russian arms, Turkey is selling drones to Ukraine who is using them to attack Russia. And Turkey, despite being a NATO member, has been at war with Greece, another NATO member.
Russia also has used internal waterways to bypass the Bosporus Straits [2].
