This is another question which is asked by many TexAu users. Here is the detailed explanation on this.
In case of single input
Unfortunately, there is no way to stop a Spice with a single input. We take the inputs from you, pass it to our servers, it starts the browser and starts running the automation. Once the request is made, it is not possible for us to get into the server and close the browser.
In case of CSV or Google Sheet input
If you're using a Google Sheet or CSV, you can easy pause / restart and resume the Spice execution by simply on pause and resume button as shown below.