If a group is the owner of the form you want to add to a flow, Power Automate doesn't list it in the Form Id.
Go to the form. Copy the Form Id from the URL of the form, and then add it as a custom value.
Send an email based on a conditional form response
When you use a form in a flow, you can add a condition that's based on how a user responds to a question in the form. The condition can test a text value or a numerical value. The condition creates two parallel branches, If yes and If no, to which you can add actions.
For example, you can use a condition to email details about a specific event or a general calendar of events, depending on how customers respond on an interest form. To learn more, follow the step-by-step instructions in Create an automated workflow for Microsoft Forms.
Convert an attachment on a form to PDF or another file type
Add your form to a flow, and then add the following actions.