Your documentation although it seems straight forward actually never works.
The dynamic sql section gives example code, it does not execute.
It does not exec in a script block or as plain sql.
Please explain limitations or where the script can actually be executed.
As a beginner starting out in postgre you can never rely on the documentation because the same thing happens, you copy the code and make your modifications and you get syntax error.
The same problem exists with the Perform statement. It does not work as advertised, you cannot execute it in a function or in a script block.
Clearly define the limitations of your language so that developers don't waste their time.
Coming from ms sql quite frankly I would never recommend postgress. The barrior to entry into actualy writing code is too great.
can you specify, please, what is wrong?
The storing procedures in ms and pg are two different worlds - and start can be difficult.