First, I should mention that you probably want api-type-signature instead beyond a certain version of Daml. This is the new name of the interface library.
Second, I’m sure you saw this if you reviewed the prior discussions, but api-type-signature is technically an internal library, though, again, you probably saw my argument why it is worth using anyway.
Finally, to answer your question, as explained in Scala 3 docs, it is possible to depend on a Scala 2.13 library from a Scala 3 project. I suggest following this path.