Amornphan 10 Set 18mm.3/4" Invisible Hidden Magnetic Buttons Snap Magnet Fastener Handbag Cloth Clasp Purse Closure DIY Sewing Tools

Can I glue then on cloth?

Can these be sewn on by hand?

I want to use these on the bottom of a curtain for metal bunk beds to they can be pulled back and held open. Will these be strong enough for that?

what is the thickness?