In case many merge requests in a gitlab group have to be deleted according to the title this snippet can be used

delete_gitlab_merge_requests.sh

#!/bin/bash

PRIVATE_TOKEN=$1
GROUP_ID=$2
TITLE_REGEX=$3
MR_STATUS=${4:-opened}
PAGE_SIZE=${5:-100}

for MR in $(curl -s --header "PRIVATE-TOKEN: $PRIVATE_TOKEN" \
  "https://gitlab.com/api/v4/groups/$GrOUP_ID/merge_requests?state=$MR_STATUS&per_page=$PAGE_SIZE" \
  | jq '.[] | select(.title | test("$TITLE_REGEX")) | [.project_id, .iid] | @csv')
  do 
    echo curl -XDELETE --header "PRIVATE-TOKEN: $PRIVATE_TOKEN"  https://gitlab.com/api/v4/projects/${MR/,*}/merge_requests/${MR/*,}
done