Nextcloud- WEBDAV - API

hi together,

i am looking in vain for a way to get a usable api query with make.com.
I can’t really figure out the javascript API. I can’t get it to work even with the make module “make an Api-Call”.
How do I manage to find a file using the ETAG, for example?
The Make modules do not offer me the possibility to search for an ETAG.
It would be great if you professionals could help me out here.
Thank you very much!
Best regards
Bernd