If you need to “host” somewhere else, you can always run the script as an automation in Zapier, so the client doesn’t “see” what you are doing. Would require having a paid zapier account, and of course changing the automation to be something triggered by Zapier.
But the bigger question is, is this a SLA where they pay you to make sure the machine is running, or are they paying you what they anticipate an hourly fee is to do the stuff manually? If they just want the output, you can always initiate and run the data in a base you own and then sync it to their bases. As long as you have access to both workspaces, that should be fine.
But also, if your current “value” to the clients is pushing the button (And knowing how to request what needs to happen when the button is pressed, ofc), it might be time to find other value adds besides being the “button presser”. That’s the only true way to protect income streams. Clients can always decide they can’t afford/don’t need you.