u/UnlikelyLunch_FunEye

How do I fix this? I’m trying to add a latch so I can fully close my door. There is a dried clay white ball in the middle that I don’t know if I need to remove. I just want to be able to use my door knob properly and lock my door. It is an interior door. Any help would be appreciated. Please know that I’m not very handy or have a lot of tools.