How can I track manual inventory adjustments in my online store?

Seems like it exists

https://admin.shopify.com/store/<STORE_NAME>/products/inventory/<INVENTORY_ID>/inventory_history?location_id=<LOCATION_ID>

When you make an inventory adjustment there is a dropdown that has a few options for “why”. Best I can imagine is an extensions app that would increase the options, let me know if you need that.