Answer
A Create command doesn't support a Using parameter — the malformed-URI error is actually the server rejecting the 'using...' clause that got embedded into the request, not a genuine syntax problem with the URI itself. If the target action requires an ETag in the header (which many bound state-change actions do), use Patch or another appropriate Test-a-rest command instead of Create — check the Test-a-rest command reference documentation for the exact syntax each command type expects, since they aren't interchangeable.