[Help] More complicated nbt selectors

I am trying to get nbt tag value from player with more complicated source "ForgeCaps.armourers_workshop:entity-skin-provider.Items.[0].tag.ArmourersWorkshop.Identifier" It's item Id nbt from armourersWorkshop mod. I can get that value using commands with /data entity @p ForgeCaps.armourers_workshop:entity-skin-provider.Items.[0].tag.ArmourersWorkshop.Identifier
and it returns id witch looks like that "db:xxxxxxxxxxxxxx".
Tried using get custom text nbt tag with this nbt selector - not working.
And is it even possible?