Seeing error "PLS-00302: component 'STPTRX9' must be declared"

Creating the Stored procedure and calling it using SQL developer throws the below error -
"PLS-00302: component 'STPTRX9' must be declared"

Below are the commands that are executed -

CREATE TABLE "DSFLOWSUSER"."TRXTEST9"
( "C1" NUMBER,
"C2" VARCHAR2(20)
);

CREATE OR REPLACE PROCEDURE "DSFLOWSUSER"."STPTRX9"(COL_IN IN TRXTEST9.C1%TYPE, COL_OUT OUT TRXTEST9.C2%TYPE)
AS
BEGIN
SELECT C2 INTO COL_OUT from "DSFLOWSUSER"."TRXTEST9" where C1=COL_IN;
END;

insert into "DSFLOWSUSER"."TRXTEST9" ("C1", "C2") values(1, 'aa');

declare
v_c1 number := 1;
v_c2 varchar2(20);
begin
"DSFLOWSUSER"."STPTRX9"(v_c1, v_c2);
dbms_output.put_line('The output column value is : ' || v_c2);