1. Confirm you're on the Monitor Scale plan
Browser checks are a Monitor Scale feature, capped at 10 per account. The create form on the Monitoring page shows an upgrade prompt in its place on every other plan.
2. Build the step list
Add steps from a fixed set of seven actions: goto (navigate to a URL), click, fill, waitForSelector, assertText, assertVisible, and screenshot. Each step is a plain selector-and-value row, not a script: there is no scripting escape hatch, so a flow that needs a conditional or a loop can't be expressed here.
3. Save and watch the first run
Browser checks run from one region (iad) no faster than every 5 minutes. The first step that fails ends the run and names itself in the down reason; a screenshot is kept for every run, and a full failure trace is kept when a run fails.
4. Read a failed run
Open the check's result to see which step failed and the screenshot of the page at that point, useful for the common failure mode a plain HTTP check can't see at all: the request succeeded, but the page rendered blank or the button never became clickable.
Go deeper
The full reference lives in the docs: Browser checks documentation. Error codes named above are each explained in the error-code reference.