The form ID will be in the URL while you are editing it - So something like Klaviyo.com/forms/XYZ
The XYZ example would be your form ID. You will need to test an opt-in to see it appear in the drop-down as an option.

Hi @lorenmn, welcome back to the Community!

Just as @Spark Bridge Digital LLC mentioned, the Form ID can be found in the URL of your browser while you are editing the form in the following format: https://klaviyo.com/forms/xxxxxx.

Additionally, another common reason why an embedded form might not be appearing on your site is that unlike popup and flyout forms, embed forms require the extra step of manual code insertion before they are visible in the storefront. This Help Center Article details the steps for embedding a form for each integration type (Shopify, BigCommerce, etc.).

In short, while the filter might very well need fixing, the form will not appear unless the above steps are completed. Here’s another active Community thread regarding a similar issue, if you’re interested :)

Another reason why the form is not appearing in your drop-down menu when creating your filter is that no one has filled out the form yet. This type of behavior is similar to a topic my colleague has described in the following Community post: 

I’m looking forward to your response and thank you for participating in the Community!

-Brian

Hi @Brian Turcotte.

Ah, yes. No-one has filled it in yet so that’s likely why it’s not showing. I did kinda wonder about this but wasn’t sure.

Feels a little ‘chicken and egg’ though. I’ll have to add myself so that I can ensure I capture all the ‘real’ sign ups.

Thanks.

Hi @lorenmn,

I’m glad I could provide some insight - here are a few more Community posts touching on this same topic, in case you would like some more perspective:

Thanks again for using the Community!

-Brian