Allowing IIS Application Pools to Access Local Folders

I was working recently with a client's ASP.Net application and had a requirement to log various items to a file log.  One of the issues was how to grant the correct user read/write permissions to folder in question.  This article explains how to grant folder permissions to the user running a given application pool.

https://docs.microsoft.com/en-us/iis/manage/configuring-security/application-pool-identities

Essentially, it involves granting "IIS AppPool\DefaultAppPool" or other application pool name (as defined in IIS) the appropriate permission.