Cannot rsync to my droplet from githubaction

I have a project that is successfully built but i cannot get github action to rsync to the droplet web folder. I have entered the private key (with the begin and end comment that surround the hash of the private key), i have enabled with ufw the SSH at port 22, somehow i get this error message: Run rsync -avz ./ @:/var/www/html

  rsync -avz ./  ***@***:/var/www/html

  shell: /usr/bin/bash -e {0}

Host key verification failed.

rsync: connection unexpectedly closed (0 bytes received so far) [sender]

rsync error: unexplained error (code 255) at io.c(231) [sender=3.2.7]

Error: Process completed with exit code 255.

Here is the github action: name: Build and Deploy

on: push: branches: [ main ] workflow_dispatch:

jobs: build: runs-on: ubuntu-latest

env:
  NODE_ENV: production
  COMPOSER_NO_DEV: 1

steps:
  - name: Checkout
    uses: actions/checkout@v4

  - name: Install Node packages
    run: npm install

  - name: Build assets
    run: npm run build

  - name: Setup PHP
    uses: "shivammathur/setup-php@v2"
    with:
      php-version: 8.3

  - name: Install Composer packages
    uses: ramsey/composer-install@v3

  - name: Upload artifact
    uses: actions/upload-artifact@v4
    with:
      name: AuthenticatorProWebsite
      path: |
        application
        vendor
        public

deploy: runs-on: ubuntu-latest needs: build

steps:
  - name: Download artifact
    uses: actions/download-artifact@v4
    with:
      name: AuthenticatorProWebsite

  - name: Prepare environment file
    run: |
      printf %s "${{ secrets.ENV_FILE }}" > .env

  - name: Deploy with rsync
    run: rsync -avz ./  ${{ secrets.DEPLOY_USER }}@${{ secrets.DEPLOY_HOST }}:/var/www/html

thank you in advance for your help