Dataflow - One or more tables references a dynamic data source

Hi. Sometimes the web urls can produce that error because it's not unique url. It's an url that will change depending on a parameter/entry/timeline/etc. That's why PowerBi can't understand the source and considers it as a dynamic source. In order to explain PowerBi that the URL is the same you need to use some parameters of the Web.Contents function. I'm talking about the first step of your code (the source with a json, it has that function inside). Check one of these posts out to understand the RelativePath and the Query parameters:
https://blog.crossjoin.co.uk/2016/08/16/using-the-relativepath-and-query-options-with-web-contents-in-power-query-and-power-bi-m-code/

https://blog.ladataweb.com.ar/post/630597294839955456/powerquery-buena-práctica-para-un-web-request

I hope that helps,