There's an option to test the dialogue flow in the dialogue's steam designer using the test dialogue option (highlighted in the below snapshot).
But per your scenario, it seems like you're not seeing the dialogue pop-up on the page itself. Are you able to confirm that you've got all the conditions set in the audience criteria section of the dialogue matched when you're trying to see the dialogue? E.g., if you have the Inferred Country set to the US in the audience criteria and are connected to a VPN of another country, then your dialogue won't pop up. I'd also double-check the URL(s) especially when you're using the wild-card URLs to see if they match with the LP URL where you're trying to see the dialogue. IMO, the most optimum and reliable way to test whether a dialogue gets invocated right as per the audience criteria of dialogue would be by adding on a test LP itself.
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