Install and resolve extension error for open cart 3

I purchased an extension from opencart marketplace which conflicts with my website and cause issues including blank page errors

Your job would be:
- make a backup of site
- fix errors on my site backup
- show a short documentation presenting it works as intended
- install it on my live site

Please write your years of opencart experience in your proposal.

Extension info: https://www.opencart.com/index.php?route=marketplace/extension/info&extension_id=30058
My website is has similar simple extension hardcoded. Conlicting codes should be resolved. It is not just a simple installation.