You can find them on Google. Many online stores are selling, and review articles can help you choose the right magnetic cable for you. I have Wsken and LSGAE cables, and they successfully keep my phone charged after the charging port wears out.
I got the ones below and I love them. I leave the two lightning ends in my iPad and iPhone, the two USB mini's in my Oculus Go and a PS4 controller, one of the USB-C connectors in my Oculus Quest. These cables let me replace many cables with one by my computer and one in my bedroom. I am actually going to order another pair next week when I get back from visiting family so I can have a cable in my car and in at work, when ever I go back to work and stop working at home.
One of the nice things about these cables is that they can transfer data too. A lot of the magnetic cables can only do power. They only do USB 2.0 (480Mbs) but it's better than nothing. I'm also going to buy a few more USB mini ends for the various battery packs I have for my Quest and Go.