Dynamic Parameters from the visulisation screen into the transform area

Hi. Working with data usually means getting all you can to store it in a place you can clean and transform before the show. This means you can work better storing all the results of the API for that slicer instead of getting the api for each users interaction. Getting all once it's healthier for the API too, you are note requesting everytime but once.

When the volumne for APIs are big or they are too complex, the best practice would be doing it before Power Bi. That means, using local code to store in a DB or notebooks to store in a lakehouse/warehouse and finally use power bi to read that.

You can try using Power Bi for this and check if it doesn't take so long. If you google web request per row or paginating api for power bi, you can find articles like this one: https://blog.ladataweb.com.ar/post/188215249200/powerquery-web-content-por-fila

That shows how to handle the request for each value of an entity. That way you load it all. The slicer will just filter a big table with the result for all of them.

I hope that helps,