How to get the Source Code of ONLYOFFICE JS files (Not Minified JS)

We are using ONLYOFFICE Version: 4.3.5 (build:14) for our Nextcloud V 12.0 application.

We want to modify the SDK JS files for our customization. But In Document server the files are minified which we are having. We can’t make any changes in that files. We need the source code unminified to make changes.

Where we can download the original source code. Please kindly suggest.

JS files which are minified are…

./cell/sdk-all-min.js
./cell/sdk-all.js
./slide/sdk-all-min.js
./slide/sdk-all.js
./word/sdk-all-min.js
./word/sdk-all.js

Thank you!