thanks! and yes - the redev has already happened. we are looking at third party tools. found something on github that seems to do the trick but am unsure. we would need to install python.
for info see: https://linkchecker.github.io/linkchecker/?fbclid=IwAR0QwZ6b4tvvE_G6F7Kn_StX62YuOgrtbIzwwkTQdD4_kpWFHdjzd0eXo_o
in terms of authentication I found https://linkchecker.github.io/linkchecker/man5/linkcheckerrc.5.html?fbclid=IwAR3Ux6BOr4xxTzZTtFVpN83_VxTI1BSnmDtoypS__Jk3CzLsKJm77YHlp94
so it looks like we could set it up on my computer with my username and login in loginuserfield and loginpasswordfield
and btw no - I'm not a developer! so I don't have dev access