My key will not go into my vw passat

The ignition key cylinder has gone bad. Some of the tumblers may have dropped. You can try a temporary fix which is hit and miss. Try spraying the opening with w40 and try angling different positions when inserting key. Another option is to use something like a slender blade or straightened large paper clip and try in seeing it into the slot. After getting the key into the ignition make sure when you take it out to insert something in its place so the tumblers don’t drop again and block the key. I usually folder a piece of paper the same size as the key and leave it in when I take out the key. You will need to get the ignition cylinder changed there is no DIY fix. I was doing this for a few months and sometimes it got trouble some when I forgot to insert something in place of the key - I have to pray the key will insert when I got back. It’s better to get it fixed to avoid any problems. I have a 2015 VW Passat and it was happening for a few months. I brought it back to the dealer and it was an expensive fix - I think it was over $600. But worth the piece of mind.