Ukraine hasn't been admitted to NATO yet from what I have read and understand is they haven't met all the conditions.
1. a European nation must demonstrate a commitment to democracy, individual liberty and support for the rule of law
Ukraine ranks 117 out of 180 countries in terms of corruption and would be the lowest member according to this index.
2. contributing to the collective defense of NATO nations.
Ukraine military until very recently wasn't all that great in terms of capability. It's why the current situation isn't turning out to be like Crimea in 2014. They are more capable today than in 2014. Though still dealing with a lot of old equipment.
3. Must be anonymous for acceptance. The obvious criteria that hasn't been met. European countries like Germany aren't sure if they should pull that trigger by bringing NATO onto Russia's border.
Ukraine has pressed for membership to defend against Russia. But President Biden and European leaders are not ready for that step.
www.nytimes.com