Getting variables from call activities using API REST (BOS 6.X)

Hello there

I have 2 process diagrams (MyDiagram1, MyDiagram2) connected by a call activity, i mapped a variable for each process, but i want retrieve/update the variable data from 2nd pool via API REST

I need it for call a DataBase connector inside the 2nd pool.

if i update the variable in the 1st pool, the 2nd takes the value and execute the connector like a charm, but now, i need to update the variable on the 2nd pool in order to execute the connector with new data