$push is not assignable to type "undefined".

[Milo123459]

Hello!

I recently started migrating from Mongoose V5 to V6 and had this one weird error coming from one of my $push operators. Here is the code and the error.

The error isn't making any sense to me, and was wondering if someone who has more experience with mongoose could take a look/help? This error is very frustrating and I've been trying to solve it for about 30 minutes but I have gotten nowhere. The documentation on the MongoDB docs for $push here have stayed the same from V3.0 to V4.0. I am using TypeScript by the way.