When I equip the backpack of the Quark Oddities, the money bag in the upper right corner will not appear, and I can only retrieve the coins by removing the backpack

Could you post a screenshot of this issue? Generally in the latest version of Numismatic Overhaul there are config options which can re-position the purse. You can access this via Mod Menu, with the /owo-config numismatic-overhaul command in-game, or in the config file

Bumping this. Are you experiencing this issue while using Sinytra or Numismatic Overhaul Reforged? If it is related to Reforged you need to report the issue to their Discord, as we do not maintain it.