Plugin for CAPI

Hi guys, how are you all?
I am a client at Facebook, and I was doing and API conversions integration, which lets me send events directly from my page’s server.
I have the following page to help: https://www.ads-software.com/plugins/official-facebook-pixel/#installation
I have a couple of questions:
1.Do you have any other type of documentation/ step by step to help in this process?
2. Is there any problem to use pixel your site plugin? (I am not a client of pixelyoursite) because this plugin it was available on my wordpress account and it was saying CAPI integration.
3. how can I fix this: PageView Event Missing Deduplication Parameter.

please and thank you in advance