Those left and right arrows and the 1/1 counter are the page navigation elements on the inventory screen. Open your DailyRewards.json and go to the 'Menu UI settings' section. The arrows are controlled by these four fields: 'Back page button (active)', 'Back page button (inactive)', 'Next page button (active)', 'Next page button (inactive)'. Each has AnchorMin, AnchorMax, OffsetMin, OffsetMax to reposition them, and 'Button Color' to change the color. The active variant shows when you can navigate that direction, the inactive one shows when you can't.