Need Google Ads and Google analytics expert

I am looking for a Google Ads and Google Analytics expert to help me with my project. My goal is to migrate from UA to GA4.

Ideal skills and experience:
- Expertise in Google Ads and Google Analytics
- Experience in UA to GA4 migration
- Knowledge of tracking website traffic with Google Analytics

Issue
1) data mismatched between U.A & G.A4
2) GA4 data is not matching with Shopify store data

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the reason for data mismatch can be
1)- U.A. is set up by the GTag manager and GA4 by Shopify preferences.

Need exact data of sale in ga4
Only U.a snippet is installed in Shopify ga4 snippet is not installed
And the measurement id is of ga4