Edge, click a button on a website using a macro

There are tools (Webdriver/Selenium) that replace the "commands" that were used for IE

this means:

you can adapt your code and use (Webdriver/Selenium) to work with Edge

.

Your first concern is that it's much more complicated, in VBA, to use this compared to the functions you're using with IE. I tried, following your question, and after a few attempts, I gave up.
Your second concern is that VBA is used less and less for this kind of thing. So you'll find very little help and very few examples in this area.

So I think you're more or less stuck. I'm thinking of these possibilities:
1) hire a professional to create the VBA you need
2) use Python instead of VBA, to fetch the data from the PMU website (so a program that does this outside of Excel)
3) wait, cross your fingers, hope that someone will propose a simple solution to integrate Edge and VBA.