Net total calculation

Hi - I have a column where an incident was opened, and a column where the incident was closed. I am trying to count the number of incidents open for a given month (i.e. Open as of 1/31/2023 - closed as of 1/31/2023). Could anyone please point me in the correct direction to solve this?

I was able to create a column in a separate table to calculate the value, however, I need it in the same table so slicers will work.

Thanks!