Using instance sharing API (spike https://folio-org.atlassian.net/browse/MCBFF-60), when creating an ECS request, create instance shadow in the secure tenant. More formally,

WHEN Three-request case (Primary + Secondary + Intermediate)
AND Primary request should be created in the non-Central tenant (always the case in the three-request case)
THEN Before creating Primary request, create Shadow instance in the same tenant where Primary request should be created

Note. Check https://folio-org.atlassian.net/browse/MCBFF-60 comment section for more information about the results of the spike and how instance sharing API should be used.