@hamade if you setup proper "Access-Control-Allow-Origin" header on your server when downloading https://fablab-shinagawa.org/jscad/designs/fruitsHolder.js you would be able to do it without proxy by direct fetch from js
this url would work then for my proto that has no proxy
https://3d.hrg.hr/jscad/three/threejscad2.html?uri=https://fablab-shinagawa.org/jscad/designs/fruitsHolder.js
for exampe if I put your script to gihtub as a gist it works
https://3d.hrg.hr/jscad/three/threejscad2.html?uri=https://gist.githubusercontent.com/hrgdavor/08e61d2014ed7b62078fa9106380f634/raw/815d639e16bfa4e88e65e2e50b6772bc17cab35a/fruit.js