SQL Replicate rows and store the relation

Using a after-insert trigger I want to replicate rows upon insertion.
Each row that gets inserted into to the table should be replicated a specified number of times.
The number of times the row should be replicated is determined by the number of active instances of an application.
Active instances are stored in another table and each row of the original table has a InstanceID column referencing the related Instance within Instances table.
The Relation between the original and replicas should be stored in another table.

Let's say the following row is inserted:

And the Instances table looks like below:

By the end of the transaction the table should be as:

And the table storing them relations would be:

I did write a piece of query to achieve this and got to the point of actually replicating it.
But what I struggle with is how to output the original id along with the newly inserted id.
It seems like I cannot reference subqueries inside OUTPUT clause and can't find any other way to do so.

This is how my query looks like:

DECLARE @insertedIDs TABLE (ReplicaID INT, OriginalID INT)

INSERT INTO TABLE1 (InstanceID, Title,...)
OUTPUT inserted.ID INTO @insertedIDs
SELECT s.ID, p.Title, ... FROM inserted as p
-- cross apply with active instances so that we will replicate once for every active
CROSS APPLY Instances_table s

--here I wish to store the mappings but i cannot get the original id inside the @InsertedIDs table to do so 
INSERT INTO InstanceEntityMappings (OriginalID, ReplicaID) 
SELECT 'I_DONT_HAVE_IT', ID FROM @insertedIDs

And I would love to know if there's a better approach in order to address this problem

I would suggest you to create a trigger on the table to handle row replication. The trigger will replicate rows based on the number of active instances and store the mappings in the InstanceEntityMappings table.

CREATE TRIGGER ReplicateRowsTrigger
ON TABLE1
AFTER INSERT
AS
BEGIN
    -- Insert the replicated rows based on active instances
    INSERT INTO TABLE1 (InstanceID, Title, ...)
    SELECT i.InstanceID, p.Title, ...
    FROM inserted AS p
    CROSS JOIN Instances_table AS i
    WHERE i.ID IN (SELECT DISTINCT InstanceID FROM inserted)
        AND p.ID IN (SELECT ID FROM inserted);

    -- Store the mappings in the InstanceEntityMappings table
    INSERT INTO InstanceEntityMappings (OriginalID, ReplicaID)
    SELECT i.ID, t.ID
    FROM inserted AS i
    JOIN TABLE1 AS t ON i.InstanceID = t.InstanceID
    WHERE i.ID IN (SELECT ID FROM inserted);
END;