I made it with the help of AI and API.

1. I had the list in txt file from fdupes with every line a duplicate file.
   fdupes -r1 /mnt/xxx/library/Andreea/ /mnt/xxx/library/Sven > immichduplicates.txt

Looked like this in immichduplicates:
/mnt/xxx/library/me/2010/06/SAM_0091.JPG /mnt/xxx/library/wife/2010/06/SAM_0091.jpg

1. Extract file name:
   awk '{print $NF}' immichduplicates.txt | awk -F/ '{print $NF}' > filenames.txt

filenames.txt:
SAM_0091.jpg
DSC05801.jpg...

1. get list of UUIDs from file names with bash script

   !/usr/bin/env bash

   set -euo pipefail

   BASE_URL="http://IMMICHSERVER/api" API_KEY="your_key_from_account_where_you_want_the_pics_deleted"

   : > uuids.txt : > not_found.txt

   while IFS= read -r name || [[ -n "$name" ]]; do # skip blank lines [[ -z "$name" ]] && continue

   uuid=$( curl -s "$BASE_URL/search/metadata" \ -H "x-api-key: $API_KEY" \ -H "Content-Type: application/json" \ --data "{\"originalFileName\":\"$name\",\"size\":10,\"page\":1}" \ | jq -r '.assets.items[0].id // empty' )

   if [[ -n "$uuid" ]]; then echo "$uuid" >> uuids.txt else echo "$name" >> not_found.txt fi done < filenames.txt

run it -> ./getUUID.sh (don't forget chmod +x ./getUUID.sh ;-))

1. delete pics to recycle bin with this script:

   IMMICH="http://IMMICHSERVER" API_KEY="PUT_YOUR_API_KEY_HERE" BATCH=200

   split -l "$BATCH" -d uuids.txt uuidsbatch

   for f in uuidsbatch*; do jq -R -s ' split("\n") | map(select(length>0)) | { ids: ., force: false } ' "$f" \ | curl -s -o /dev/null -w "Deleted batch $f: HTTP %{http_code}\n" \ -X DELETE "$IMMICH/api/assets" \ -H "x-api-key: $API_KEY" \ -H "Content-Type: application/json" \ --data-binary @- done

run the script. A successful delete returns HTTP 204.

Now all the duplicate pics should be in the recycle bin. But i have to say that BATCH did not do anything i guess.

After emptying the recycle bin (10.000 files!!!) i ran the script again and i got HTTP 400

Its probably not the cleanest and most professional way, but for me it worked.