Step 1. Copy the file ID
Your Google Drive share link probably looks like:
https://drive.google.com/file/d/FILE_ID/view?usp=sharing
Grab just the FILE_ID part.
Step 2. Use the preview link in an iframe
<iframe src="https://drive.google.com/file/d/FILE_ID/preview" width="100%" height="600" allow="autoplay"></iframe>
Make sure your sharing permissions are set to:
Anyone with the link → Viewer
Step 3. Publish/Preview
On Hostinger, sometimes the embed won’t work in the editor preview, but it does work once you publish the site. If it still asks for access after publishing, double-check that you didn’t accidentally share the folder but left the individual PDF private — Google can be picky.