function onFFClipboardResponse (event) {
        if (event.detail.key === key) {
          resolve(event.detail.value)
          document.removeEventListener(
            'ff53054c0e13_ffclipboardResponse',
            onFFClipboardResponse
          )
        }
      }
Gets a value from the ffclipboard.
@param {string} key - The key to get the value for.
@returns {Promise<any>} A promise that resolves with the value.