Give commands:
function interactions:chair/give_maker
function interactions:chair/give
function interactions:npc/give_maker

Place chair:
Use "Place Chair" Spawn egg to place chair in any direction you are looking at (oak stairs).

Make chair:
Use "Make Chair" Spawn egg to create a sitting place of any block you click on..

Destroy chair:
Break the "chair"-block at its bottom (or break the block below on thin blocks like trapdoors/presure plates)

Place NPC:
Use "Place NPC" Spawn egg to place an NPC, right-click NPC to start conversation (this one is customizable within the data pack).

View chair:
Press F3 & B to view hitboxes of the interaction entity.