Get an output from a Python function in Snowflake SQL

I have the following code, which is supposed to return the value "Procedure executed successfully" into the my_var variable, but it's give me an error message that reads

"Syntax error: unexpected 'INTO'. (line 17) syntax error line 7 at position 2 unexpected 'RETURN'. (line 17)"

CREATE OR REPLACE TEMPORARY PROCEDURE my_python_proc()
RETURNS STRING
LANGUAGE PYTHON
RUNTIME_VERSION = 3.11
HANDLER = 'run'
AS
$$
def run():
    return "Procedure executed successfully"
$$
;

DECLARE my_var STRING;

BEGIN
  //LET my_var := CALL my_python_proc();
  EXECUTE IMMEDIATE 'CALL my_python_proc()' INTO :my_var;
  -- Use the variable, for example:
  RETURN my_var;
END;

Show VARIABLES;

Am I doing something wrong?

I am expecting the "my_var" variable to be set to "Procedure executed successfully"

EXECUTE IMMEDIATE is used for dynamic SQL and it is completely unnecessary in this context. You can use:

• direct assignment - variable := (CALL ...)
• CALL ... INTO :variable syntax

CREATE OR REPLACE TEMPORARY PROCEDURE my_python_proc()
RETURNS STRING
LANGUAGE PYTHON
RUNTIME_VERSION = 3.11
PACKAGES = ('snowflake-snowpark-python')
HANDLER = 'run'
AS
$$
def run():
    return "Procedure executed successfully :)"
$$
;

Main query:

DECLARE 
  my_var STRING;
BEGIN
  -- option 1 using direct assignment
  my_var := (CALL my_python_proc());

  -- option 2 using CALL INTO
  CALL my_python_proc() INTO :my_var;

  RETURN :my_var;
END;

Output:

Side note: SHOW VARIABLES is for session variables which are different from Snowflake Scripting variables.