Hello @Javier_Plaza_Go 
First of all you need to know some of the basics of how airtable scripting is works.

There are 2 ways you can run scripts on airtable.
1. Automation scripting block
2. Extension Scripting

An automation's scripting action runs a script in the background of the base. This differs from the Scripting extension, which runs a script in the foreground. For scripts that you would rather run manually, the Scripting extension is the ideal tool.

While you run the Automation script it's run on the Airtable server and the Extension script is run on our browser.

The automation script is run(called) automatically while the extension script always needs to run manually.

There are some limits and advantages to using both of them based on it's use case.
👍

That's only available in the scripting extension; check out the docs here: https://airtable.com/developers/scripting/api/output#markdown

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There's a lot going on in your post and I think you might be going down the wrong path?  If you could explain what you're trying to do exactly we might be able to provide advice on how you could try to achieve it, be it through automations or Make etc

Ok, understood. 

Basicaly I´m trying to set up a button which checks conditions on records, and then open an URL on the browser, or markdown link, contained on those records, on a field. I have been trying to set a Make Automation, but its quite difficult, even to send a Google notification.  

Thanks a lot. 

When you say "open a URL", you mean you want the user to be brought to this URL?  Or does this URL activate a webhook or something?

I mean the user to be brought to the URL in the browser. 

Ah, that's not possible via an Airtable automation or scripting extension I'm afraid.  Your best bet would be to use a Make webhook for this; the webhook would trigger the scenario and do the filtering actions you mentioned, then you'd use the "Webhook Response" module to do a redirect to the URL the previous modules found