await interaction.editReply(`Done! I counted to ${number}`)
                .then(message => setTimeout(() => message.delete(), 3000))

This gives an error while trying to delete a reply message in DM on Discord:

TypeError: message.delete is not a function

However it perfectly works in server channel. I would use deleteReply() but this does not work when you have edited the reply with editReply(). I should note though that deleteReply() for deleting a message that has not being edited works on DM and servers.