Chances are it's not packaged for your favorite OS, so you'd have to build it yourself.
The next thing on the plate for that project is to support the GNU C preprocessor line annotations so that if Egawk is handed preprocessed code, it will report errors against the original file and line number.
In the past I've forked at the sign of any resistance.
I have a fork of GNU Awk called Enhanced GNU Awk (egawk).
https://www.kylheku.com/cgit/egawk/about/
It has a let construct for lexical variables.
Chances are it's not packaged for your favorite OS, so you'd have to build it yourself.
The next thing on the plate for that project is to support the GNU C preprocessor line annotations so that if Egawk is handed preprocessed code, it will report errors against the original file and line number.