The mod contains backwards compatability mechanics for the datapack.

First, you should remove the datapack, as the mod and datapack are not intended to be used in tandem (It doesn't matter if you remove the datapack before or after installing the mod).

If it detects the datapack was previously used, it will enable the tooltrims_deleteToolsmithingTable gamerule, which destroys smithing tables within 6 blocks of players and drops its ingredients (2 copper and 4 planks). This can be reversed using /gamerule tooltrims_deleteToolsmithingTable false. You can also enable the legacy resource pack, which makes templates and toolsmithing tables look right before they are upgraded or deleted.

You can use the command /tooltrims upgrade to upgrade the tool or template you are holding so it uses the code trim system instead of the datapack trim system. Templates from the datapack cannot be used in the smithing table until you upgrade them. For tools, the difference is only noticeable if you look at the NBT/component data or if you try to re-trim the tool, in which case both the old and new trims will show up in the tooltip.