for me to sell on offerup i have to d/l the app. ?
Yes, you have to download and install the app in order to be able to sell. It is only comapatible with Android and iOS devices.
Welcome to the community forums, @cpu999-1!
Yes, to post an item for sale on OfferUp, you will need to download the app. Currently, it's not possible to post items from a computer.