Simple, Its not possible to make a Hephaestus Forge in The Beyond something i think should be possible since its advertised as a place to make a base

(0.2.36) Just tested this, seems to work perfectly fine, ensure you have the correct blocks, and layout, as highlighted in the F&A wiki, and pictured below
https://wiki.valhelsia.net/external-mods/forbidden-and-arcanus/wiki/blocks/hephaestus-forge

did you place the table or try to create it?

created with a smithing table and dust, shift right clicked the table with the dust