I know that I can do keyword research, but there is also websites like
SemRush.com, where with paid subscription, I can probably get some kind of keywords too. I dont think I can get all keywords per domain there with a regular plan, I think that they charge more for that (custom report).
What other options would be for this. I know that there is at least several competition research websites, who offer that for a fee too.
What could be a good way of getting something like this, and something that would be working? It can be paid.