Actually I've done Doordash for over a year now. Doordash does keep track of your mileage through the app that they give you the deliveries on, along with having the in app GPS/map there to give you directions along your route. I have Everlance to keep the mileage log myself, and it's extremely close to what Doordash reported as mileage through their own records.
I'm actually just looking at where to enter this information myself; but the mileage they do give you.
This would be somewhat easier if the IRS opened up a tax filing caregory for these online apps for Gig workers specifically; as your contract work is technically self employed, but it's through a mobile app from an actual company who wants to pay you as self employed, even though you are really doing the work for a platform. For those not familiar, Doordash is the same as Uber eats, and in fact ride sharing apps, except it does deliveries rather then taxi one around.
