Google: "study Twitter accounts propaganda news". Start digging. There's a lot of secondary news and primary sources from independent researchers. There are patterns of how tweets travel between groups of popular accounts. There are known rings of accounts which are excited in Russian about Crimea one month and then in French about Macron the next month. There are groups of accounts constantly replying with Russia praise 9-5 Moscow time.
As much as I hate the "do your research" response, there are so many articles already out there, I don't even know where to start and not seem arbitrarily selective.
At this point there have been so many claims of election interference with nothing to prove it so I have no qualms about simply dismissing yours unless you deem it worthwhile to back up your claims.
I'm not doubting that they interfered, I just haven't seen any evidence of it and you haven't helped at all.
Each story is present it a few places - sourced mixed to reduce bias. We may never know what was the scale of the influence, so that's the debatable part. But unless someone claims that popular social media accounts have no influence over the results, they agree that IRA did play a part.
You could also speculate that IRA is not led by silly people eager to waste government money for internet LOLs. If their efforts were not effective, why do they continue that for years?