(module

  (func (export "rotate_right") (param $num i32) (param $by i32) (result i32)
    ;; load the number to rotate and the by how many spots
    local.get $num
    local.get $by

    ;; rotate and return the result
    i32.rotr
  )

)
var url = "{%wasm-url%}";
await WebAssembly.instantiateStreaming(fetch(url), { console }).then(
  (result) => {
    const rotate_right = result.instance.exports.rotate_right;

    let res = rotate_right(0b00000000_00000000_00000000_00000111, 1);
    console.log(numToBin(res));
  }
);

function numToBin(num) {
  return (num >>> 0).toString(2).padStart(32, "0").match(/.{1,8}/g).join("_");
}

Wat Demo: rotr