How to set "VARSIZE" and "SET_VARSIZE" in PostgreSQL 16 Ubuntu

I am following this tutorial on how to install your own OSM server using Ubuntu 20.04.

In step number 2 it showed me an error when trying to run the command

make debIt seems that a variable declaration is missing.In this post in stackoverflow How to set "VARSIZE" and "SET_VARSIZE" in PostgreSQL 16they explain that in PostgreSQL 16 they separated the variables in another file called varatt.h. That to solve the error I must add that file, but I don't know where I should add it.

I have tried to insert the file into others such as osml10n_translit.cpp, kanjitranscript.c and postgres.h, but it does not work, it gives other errors about other variables.

I'm really lost here. Help Please..