Once you activate the Mod

Press
Left Ctrl + Left Alt + F8,
or Left Ctrl + F6,
or Left Ctrl + N (recommended)
to enable this mod’s command window.

Once you activate the window
It should be look like this↓

“MoreTotem - 图腾槽扩展”
MoreTotem - Totem Slot Expansion
Extra: 0 (Total: 2, Max 72) [+]
Tip: Newly added totem slots may require scrolling in the equipment bar to be visible.
This feature allows you to directly modify your equipment’s totem and gem slots within the gear interface,
so you can simply adjust the upper limit as needed.
Note: If you want to delete extra slots that you’ve added, make sure to unequip any totems placed in those slots first, otherwise the totems will be lost.

“宝石槽（当前目标）”
Gems: 0 [+]
说明：先打开物品详情，再按 F9 锁定；修改后重新选中该物品可刷新显示。
[恢复当前目标的宝石槽]
[立即检测 (F9)] [清除目标]

Gem Slot (Current Target)
[Restore Current Target’s Gem Slots]
[Detect Now (F9)] [Clear Target]

How to modify weapon gem slots

You need to open the weapon details page of the weapon you want to modify
(the one where you can attach parts),
then click the bottom-left button “[立即检测 (F9)]” or press F9.
You should now be able to modify the gem slots of the current weapon.
The button above “[立即检测 (F9)]”, “[恢复当前目标的宝石槽]”,
means to reset the current target’s gem slots.
The button to the right, “[清除目标]”, means to clear your current weapon selection (re-select the target).

Below that is the author’s original description:
“Note: Open the item details first, then press F9 to lock; after modifying, reselect the item to refresh the display.”

打开窗口热键：LeftControl + LeftAlt + F8
[重新绑定] [恢复默认]
[Dump 常用 API 摘要]

Hotkey settings for opening the mod window
Open window hotkey: LeftControl + LeftAlt + F8
[Rebind Key] [Reset to Default]
[Rebind Key (translated)] [Reset to Default]
[Dump Common API Summary]

引用自 阿斯：

Notes
When reducing the number of slots, make sure to remove any items from the corresponding slots beforehand, otherwise they will be lost.
After modifying the equipment bar UI, this mod may conflict with other mods that also modify the equipment bar.
When scrolling the equipment bar up or down, make sure your mouse cursor is placed over an equipped item. You cannot scroll when hovering over an empty slot.

Common Issues
Laptop users or keyboards with an FN key may need to activate the Function Key (F1–F12)
When the storage (inventory) window is open, double-clicking an equipped item will send it directly into storage — it has not disappeared.
This mod will only cause a totem to vanish if you remove a slot that currently has a totem equipped.