Now, there are two primary reasons for redirecting backlinks:

To redirect inbound links going to a web page to another URL on the same domain (e.g., the content moved or the original page was deleted).
To redirect inbound links going to an old domain over to a new domain to pass link equity for SEO value.
We’ll cover both of these redirection strategies below so you know how to set up proper 301 redirects to save all of the PageRank value from incoming backlinks etc

https://we.riseup.net/batatempel/redirect-backlinks-for-seo