Facebook Pixel expert needed to fix pixel issues on my Shopify website

PLEASE DO NOT SEND GENERIC/AUTOMATED REPLIES. Any such replies will be ignored as I’m looking for experts who take the time to address the issue at hand precisely. I'm looking for someone with expertise on fixing Facebook pixel issues relating to Shopify websites. The pixel was installed on my Shopify website ([login to view URL]) on 23-May 2021 and has been working fine since. However, recently I noticed about 20-30% of the purchases not being registered in the Facebook Ads manager and after checking the Facebook Event manager, I found couple of errors had been flagged up, which might explain the issue. Looking at the solution suggested by Facebook, it seems some minor coding tweak is required to fix the issue (please see the screenshots included). I am particularly interested in hearing from experts who have resolved this issue in the past. If you are interested in helping then please state your past experience in fixing such issues and briefly outline how you will go about fixing these particular issues. Finally, if you can, it will be helpful if you could estimate how long you expect to take to fix this, so that I can get an idea of the repair costs. Best Regards, Umar