Just mention several platform I use such Tumblr, Minds, Gab, etc. I usually use view-sorce to inspect it, but I just curious if there any efficient method without asking them first.
As far as I know, Tumblr allows you to republish articles, you need to add the canonical URL in the "Content source" field. As for the rest, I guess you'll have to do a bit research on your own, I'm not familiar with the platforms you've mentioned.