Hamas has denied Israeli claims that it uses schools, hospitals and other civilian facilities for military aims.
We've seen recent video footage of Hamas tunnels accessed via hospitals, and reports about Hamas using hospitals, schools, and mosques to hide weapons goes back decades.
They may be bullshit, but they're very easy to find with a search engine.
https://www.nbcnews.com/news/world/israel-video-hamas-hostages-al-shifa-hospital-tunnel-gaza-rcna125948
Pretty sure this video has snippets from the one I saw a few weeks or months ago:
https://www.youtube.com/watch?v=nJxejSK03Ik&rco=1