How do you run a stored procedure from a script in Toad to test it?

I don't know why this is so not straightforward. I do not want to use any Toad automation features nor the data binding dialogs. I just want to to my tests by running a script and seeing results in the regular editor window results pane.

This uses global variables (because I saw this work once, does not now). I don't care what kind of variables I use, I just want to run the stored procedure from a Toad editor and get a result. How can this be implemented? Toad complains on this right at the SET TEST.P_DATA

This is the sproc test script below

create OR replace VARIABLE TEST.P_DATA VARCHAR(50);
create OR replace VARIABLE TEST.O_RESPONSE_DATA VARCHAR(4000);

-- Set the input parameter value
SET TEST.P_DATA = 'TestData1';

CALL TEST.MY_PROC(P_DATA, O_RESPONSE_DATA);

-- Output the result
SELECT TEST.O_RESPONSE_DATA
from SYSIBM.sysdummy1;

This is actual script, I left out the schema on the original in the sproc call

This is the sproc test script below

create OR replace VARIABLE TEST.P_DATA VARCHAR(50);
create OR replace VARIABLE TEST.O_RESPONSE_DATA VARCHAR(4000);

-- Set the input parameter value
SET TEST.P_DATA = 'TestData1';

CALL TEST.MY_PROC(TEST.P_DATA, TEST.O_RESPONSE_DATA);

-- Output the result
SELECT TEST.O_RESPONSE_DATA
from SYSIBM.sysdummy1;