first of all, you have to find the culprits - it was just by chance Liba found this on Minds.
there are services (that cost an arm and a leg) that would patrol the web for you and send you reports.
The site is a Canadian company:
https://tineye.com/
a basic search you can conduct yourself (from their home page) is free, but if you go pro to get all the bells and whistles, then it will cost - there is a choice of products:
https://tineye.com/products
Once you got that, here are some useful links:
https://sarafhawkins.com/how-to-file-dmca-takedown/
https://www.socialmediaexaminer.com/how-to-submit-dmca-takedown-notice/