The error "PLS-00306" means the number or type of arguments passed to the procedure ADDVALUES does not match its definition.

Check the Oracle procedure ADDVALUES to confirm it takes exactly 3 parameters: 2 IN parameters (numbers) and 1 OUT parameter (number).

If the procedure is inside a package, the package name must be provided in the PKGName input in OutSystems. In OutSystems, create a structure with 2 integer fields, for example P1 and P2, and pass it using ToObject(p\_value) in the Parameters input.

Create a text variable like ResultText to capture the OUT value using the SimpleOutputs input.

 Leave the SimpleOutputTextSize to a sufficient value like 50 or 100 to ensure the returned number can be stored.

 Set the SPName input to ADDVALUES exactly as it appears in Oracle, case-sensitive if needed.

If PKGName is blank, the procedure must be a standalone one and not inside any package.