Okay so I was trying create a search function by passing the input value to my query, $contains must be the value of what the user puts in the input field.

const qs = require("qs");
  const query = qs.stringify({
    filters: {
      $or: [
        {
          blogTitle: {
            $contains: "",
          },
        },
        {
          blogContent: {
            $contains: "",
          },
        },
      ],
    },
    encodeValuesOnly: true,
  });
  const data = await fetch(`http://localhost:1337/api/blogs?${query}`);
  const newData = await data.json();